noun
domestic duck
Refers specifically to the domesticated duck, as opposed to wild ducks (鴨, かも).
公園の池にアヒルがたくさんいる。
There are many ducks in the park pond.
アヒルの卵は鶏の卵より大きい。
Duck eggs are larger than chicken eggs.
Very rare kanji form; practically never used.
鴨 refers to wild ducks in general, while アヒル specifically means the domesticated duck.
The word is likely of native origin, with the kanji 家鴨 (house duck) and 鶩 being later assigned ateji. The exact derivation is uncertain.