English: lagoon
Welsh: morlyn
Subject: Amgylchedd
Welsh definition: An area of salt or brackish water separated from the sea by low sand-banks or a similar barrier.
Plural: môr-lynnoedd
Notes: Dyma’r term i’w ddefnyddio wrth gyfeirio at ddŵr môr a datblygiadau arfordirol. Mewn cyd-destunau eraill, ee wrth ddisgrifio pyllau slyri, defnyddier ‘lagŵn’.