What is the difference between Deniz and Derya?

Both mean “sea”. Deniz is Turkic (Old Turkic teŋiz); Derya came into Ottoman Turkish from Persian daryā.

Are Aksu and Akarsu built the same way?

No. Aksu is adjective + su, “clear water”. Akarsu joins akar, “flowing”, from akmak, with su; it is a dictionary headword meaning “running water”.

What does Çağlayan mean?

It is the participle of çağlamak, “rushing, babbling”; TDK also gives it as a noun for a waterfall.

Category·Nature and landscape·186 surnames

Water, sea and rivers

Surnames: 186; in this dictionary
In the national top 30: 0; ADNKS 2025

How did these surnames come about?

The Old Turkic form of deniz, “sea”, is usually given as teŋiz. The same root survives in other Turkic languages for a large body of water. In Turkish the sound has shifted a little and the meaning has stayed put. Today Deniz is both a surname and a popular given name; this hub deals with it as a surname.

Words from the water

Surnames here come from general words for water and bodies of water. Irmak, çay and dere are the steps of a river's size, from river to brook. Pınar is water rising from the ground on its own, a spring; older texts write it bınar. Kaynak means both “source of a stream” and “origin” in general, so the surname carries both senses at once. Çağlayan is the -(y)An participle of çağlamak, “to rush, to babble”, giving “rushing”; the TDK dictionary also lists it as a noun for a waterfall.

Derya arrives by another road. Persian daryā settled into Ottoman Turkish as a word for the sea and was much used in poetry. So the hub holds two words for sea side by side, one Turkic and one Persian: Deniz and Derya.

Compounds in -su

The most productive pattern is “adjective + su”. Aksu is “white, clear water”, Göksu “blue water”, Karasu “dark water”. Akarsu is built differently. The aorist adjective akar, “flowing”, from akmak, joined su to make a single word, “running water”, which TDK lists as a headword. Some of these compounds are also the names of real rivers. Here the general dictionary sense is what counts; proper names such as Fırat, Dicle and Aras are filed with the place-name hubs.

The 1934 obligation

The Surname Law made it compulsory for every Turk to carry a surname. It was published in the Resmî Gazete in July 1934 and entered into force six months after publication. In that window millions of families had to settle on a name. Water words were easy, inoffensive choices.

What it is not

Agent nouns in -CI, such as Sucu “water seller”, Gemici “sailor” and Kayıkçı “boatman”, name trades and belong elsewhere. Rain, flood and deluge sit in the weather hub. This one is about water itself, still or flowing.

A last detail: Deniz, Derya and Pınar appear in the registers both as women's given names and as surnames. A surname that doubles as a given name says nothing about whether that name was ever used in the family.

Sources^1,2,3

All surnames in this category

The list grows as surnames are added to the dictionary.
#	Surname	Meaning	Origin	Letters
01	Ada	island	Turkic	3
02	Adalı	islander	Turkic	5
03	Adanur	island of light	Arabic	6
04	Adatepe	island hill	Turkic	7
05	Ağçay	white stream	Turkic	5
06	Akan	flowing	Turkic	4
07	Akar	flowing	Turkic	4
08	Akarca	small stream; hot spring	Turkic	6
09	Akarcalı	from Akarca (“little stream”)	Turkic	8
10	Akardere	flowing stream	Persian	8
11	Akarsu	running water, stream	Turkic	6
12	Akbulak	white spring	Turkic	7
13	Akbunar	clear spring	Turkic	7
14	Akçay	white stream	Turkic	5
15	Akçayöz	essence of the clear stream	Turkic	7
16	Akdeniz	the Mediterranean	Turkic	7
17	Akgöl	white lake	Turkic	5
18	Akıcı	flowing, fluent	Turkic	5
19	Akış	flow, flowing	Turkic	4
20	Akkaynak	clear spring	Turkic	8
21	Akmaz	still water, backwater	Turkic	5
22	Akpınar	white spring, clear source	Turkic	7
23	Aksu	clear water, white water	Turkic	4
24	Aksular	clear waters	Turkic	7
25	Alabora	capsizing	French	7
26	Alpsakarya	hero of the Sakarya	Greek	10
27	Altındere	golden brook	Persian	9
28	Altınkaynak	golden spring	Turkic	11
29	Altunbulaklı	of the “golden spring”	Turkic	12
30	Altunkaynak	golden spring	Turkic	11
31	Aqçoqraqlı	from Akçokrak (“white spring”)	Turkic	10
32	Aral	island	Turkic	4
33	Aras	the Aras river	Other	4
34	Araz	the river Aras	Persian	4
35	Arda	Arda River; marker stake	Other	4
36	Ardalı	of the Arda	Other	6
37	Ark	irrigation ditch	Turkic	3
38	Aydeniz	moonlit sea	Turkic	7
39	Ayengin	vast as the moon	Turkic	7
40	Aysu	moon water	Turkic	4
41	Bahri	of the sea, seaman	Arabic	5
42	Baransel	rain torrent; wealthy	Arabic	8
43	Baransu	rainwater	Turkic	7
44	Barka	large rowing boat	French	5
45	Başgöze	head spring, source	Turkic	7
46	Başpınar	head spring, source	Turkic	8
47	Baykal	name of Lake Baikal	Turkic	6
48	Bender	port; Bender (fortress)	Persian	6
49	Bengisu	water of life	Turkic	7
50	Beşpınar	five springs	Turkic	8
51	Bingöl	a thousand lakes (place name)	Turkic	6
52	Birkiye	pool, spring	Arabic	7
53	Bulak	spring, source	Turkic	5
54	Bulakbaşı	spring-head, source	Turkic	9
55	Cansel	surge of life	Arabic	6
56	Cansu	soul + water	Turkic	5
57	Ceyhun	old name of the Amu Darya	Arabic	6
58	Coşkunsu	gushing water	Turkic	8
59	Cumbul	splash	Turkic	6
60	Çağlar	rushing, gushing (water)	Turkic	6
61	Çağlayan	cascade, small waterfall	Turkic	8
62	Çağlayangil	the Çağlayan family; waterfall	Turkic	11
63	Çağlıyan	cascade, rushing water	Turkic	8
64	Çay	stream, small river	Turkic	3
65	Çaylıgil	the Çaylı family; by the stream	Turkic	8
66	Çayoğlu	son of the stream (or tea)	Turkic	7
67	Çeşmelioğlu	son of the Çeşmeli	Persian	11
68	Çiftpınar	twin spring	Turkic	9
69	Çoruh	a river flowing into the Black Sea	Other	5
70	Dağpınar	mountain spring	Turkic	8
71	Dalay	sea, ocean	Mongolic	5
72	Dalyan	fish weir	Greek	6
73	Deniz	sea	Turkic	5
74	Denizci	seaman, sailor	Turkic	7
75	Denizer	man of the sea	Turkic	7
76	Denizeri	seaman, sailor	Turkic	8
77	Denizolgun	mature as the sea	Turkic	10
78	Dere	brook, stream	Persian	4
79	Derebaşı	head of the valley	Turkic	8
80	Dereli	by the stream; from Dereli	Persian	6
81	Derin	deep, profound	Turkic	5
82	Derya	sea	Persian	5
83	Doğançay	falcon stream	Turkic	8
84	Duru	clear, limpid, pure	Turkic	4
85	Durul	become clear; form of Tuğrul	Turkic	5
86	Durusu	clear water	Turkic	6
87	Düzakın	straight onrush	Turkic	7
88	Eğridere	winding stream	Persian	8
89	Engin	vast, boundless	Turkic	5
90	Engindeniz	the vast open sea	Turkic	10
91	Erbulak	the hero’s spring	Turkic	7
92	Erdeniz	a brave man vast as the sea	Turkic	7
93	Ersel	man like a torrent	Arabic	5

Common questions

What is the difference between Deniz and Derya?: Both mean “sea”. Deniz is Turkic (Old Turkic teŋiz); Derya came into Ottoman Turkish from Persian daryā.
Are Aksu and Akarsu built the same way?: No. Aksu is adjective + su, “clear water”. Akarsu joins akar, “flowing”, from akmak, with su; it is a dictionary headword meaning “running water”.
What does Çağlayan mean?: It is the participle of çağlamak, “rushing, babbling”; TDK also gives it as a noun for a waterfall.

Sources

1Türk Dil Kurumu, TDK Güncel Türkçe Sözlük
2Sevan Nişanyan, Nişanyan Sözlük
3T.C. Resmî Gazete / Mevzuat Bilgi Sistemi (mevzuat.gov.tr), Soyadı Kanunu (Kanun No. 2525)