おおうみうま 大海馬 LinksSentence search for 大海馬Sentence search for おおうみうまSentence search for オオウミウマKanji details for 大, 海 and 馬Edit in JMdict Noun1. great seahorse (Hippocampus kelloggi); Kellogg's seahorse; offshore seahorseUsually written using kana aloneOther formsオオウミウマ Discussions Log in to talk about this word.