Wales has over 2500 km of coastline, which is quite a lot for a very small country! Five of Wales’ seven cities sit on the coast, and even where I grew up in mid-Powys, one of the most inland parts of Wales, you were hardly ever more than an hour away from the seaside. The Welsh word for sea is môr, and the plural is moroedd.
môr
sea
As you can hear, the accent on the ô (we call it to bach or little roof) changes the quality of the sound, so that it rhymes with English roar or core. Môr is different to mor, which is a common particle meaning so or how, and is pronounced with a much shorter o sound, like in sorry. Never forget the to bach!
Môr comes from the proto-Brythonic *mor, and there are similar words in the other Brittonic languages, Cornish and Breton. It can mean both sea and ocean, although ocean is also often translated as cefnfor (literally: back sea). This is a bit like the word for countryside, cefnwlad (literally: back country), which combines cefn and gwlad. There’s also a specific word for the deep sea, which is dyfnfor.
Coast is arfordir or ar lan y môr. One of my favourite songs to sing in school was Lawr ar Lan y Môr (Down by the Seaside), in which the narrator falls in love with a beautiful girl who lives by the sea.
You can hear it sung by well-known Welsh folk singer Gwilym Bowen Rhys below.
Here’s how môr mutates:
Soft mutation
fôr
Nasal mutation
N/A
Aspirate mutation
N/A
Môr and cefnfor are both masculine nouns, which is why they don’t mutate after the definite article.
For the most part, the names of the world’s famous seas and oceans are similar in Welsh to their English counterparts – for example, the Red Sea is y Môr Coch, the Dead Sea is y Môr Marw, and the North Sea is Môr y Gogledd. One that’s a bit different, though, is Cefnfor yr Iwerydd (the Atlantic Ocean). My personal favourite is y Cefnfor Tawel (the Pacific Ocean). Literally, it means the quiet ocean.

If you’re looking to go for a swim in y môr (the sea), you’ll need to head down to the arfordir with your gwisg nofio (swimming costume) and maybe even an astell beiston (surfboard). If you’re more interested in travelling tramor (overseas), you could think about becoming a morwr (sailor) and setting out on a mordaith (sea voyage), though you’ll need to be careful you don’t end up suffering with sâl môr (seasickness)!
Mae hi’n byw ar lan y môr.
She lives by the seaside.
And of course, there are all sorts of interesting (and sometimes scary) sea creatures that you might come across on your anturiau (adventures).
- morfil = whale, also used for sea monster
- sglefren fôr = jellyfish
- seren fôr or seren bigog = starfish
- morlo = seal
- octopws = octopus
- pysgod = fish
- morflaidd = various species of fish: shark, bass, wolf-fish
- siarc or morgi = shark or dogfish
- morfarch = seahorse or walrus (sometimes also hippo!)
- morgath = rayfish
- dolffin = dolphin
Did you know that the Welsh county Ceredigion (Cardiganshire) is one of the only two British coastlines with a permanent population of dolffiniaid trwynbwl (bottle-nosed dolphins?)
Dw i eisiau nofio yn y môr.
I want to swim in the sea.

Môr can also be used figuratively to refer to abundance or plenty. One well-used Welsh idiom is gwneud môr a mynydd, which means to blow out of proportion. It literally translates to making a sea and a mountain, so it’s a bit like the English idiom making a mountain out of a molehill.
The most important way in which môr turns up in Welsh culture is in the national anthem, where the sea is described as yn fur i’r bur hoff bau (the border to the purest, best-loved land). The lyrics plead for the Welsh language to live on for as long as the sea serves as such a border: i.e., forever.