くちかた 口が堅い Show inflections LinksSentence search for 口が堅いSentence search for くちがかたいSentence search for 口が固いSentence search for 口がかたいKanji details for 口 and 堅Edit in JMdict Expressions (phrases, clauses, etc.), I-adjective (keiyoushi)1. tight-lipped; able to keep a secretSee also 口の堅い, Antonym: 口が軽いOther forms口が固い 【くちがかたい】、口がかたい 【くちがかたい】 Discussions Log in to talk about this word.