The Japanese word for duck is
鴨

かも - kamo

Japanese Definition

duck
1. 名詞. 鴨かも、家鴨あひる
2. 名詞. 鴨の肉にく、家鴨の肉
3. 名詞. （クリケット）0点
4. 名詞. （英）かわいい人
5. 名詞. ====学名====
6. 名詞. Anas platyrhynchos
7. 名詞. Cairina moschata
8. 名詞. ====(comps)====
9. 名詞. (top3)
10. 名詞. break one's duck, break the duck
11. 名詞. Burdekin duck
12. 名詞. dabbling duck
13. 名詞. diving duck
14. 名詞. duck-arsed
15. 名詞. duck-footed
16. 名詞. (mid3)
17. 名詞. duckbill
18. 名詞. duck-billed
19. 名詞. duckboard
20. 名詞. duckling
21. 名詞. ducks and drakes
22. 名詞. ducks on the pond
23. 名詞. lame duck
24. 名詞. (mid3)
25. 名詞. odd duck
26. 名詞. Peking duck
27. 名詞. quack like a duck‎
28. 名詞. shelduck
29. 名詞. sitting duck
30. 名詞. take to something like a duck to water
31. 名詞. (bottom)
32. 動詞. ひょいとかがむ。
33. 動詞. ひょいと引ひっ込こめる。
34. 動詞. （水に）ひょいといれる。
35. 動詞. （責任など）のがれる。

鴨
1. n. a duck
2. n. (slang) (from the way ducks return to the same place and are thus easy to hunt) a mark or easy target for a swindle, someone who is likely to lose at gambling or other competition
3. n. (slang) (from the good flavor of duck meat) short for 鴨の味: a very good flavor; by extension, any remarkably good sensation or feeling, particularly describing happy married life
4. n. (slang) (from the uniform of black clothing) short for 黒鴨: a male servant, such as a butler or chauffeur (compare English penguin)
5. n. Usage: As with many terms that name organisms, this term is often spelled in katakana, especially in biological contexts, as カモ
6. n. (rare) alternative spelling of ja 家鴨 : a domestic duck, Anas platyrhynchos var. domesticus, descended from the mallard

カモ
1. n. 鴨: duck

家鴨
1. n. a domestic duck (a domesticated variety of mallard)
アヒルの子 - a baby duck, a duckling
2. n. (slang often, derogatory) a woman who is short and has a large butt
3. n. an academic grade of “B” (from the way the 乙 character, used to indicate this grade, looks vaguely like a duck)
4. n. (military) an amphibious truck (from the (cog, en, duck))
5. n. Usage: As with many terms that name organisms, this term is often spelled in katakana, especially in biological contexts, as アヒル
6. n. a domestic duck