How do you say sheep in Japanese?
— 羊 (ひつじ, hitsují)

Generic synonyms for sheep in Japanese
simple簡単 (かんたんな, kantan-na); 単純 (たんじゅんな, tanjun-na); 易い (やすい, yasui)
Specialized synonyms for sheep in Japanese
ram牡羊, 雄羊