adjectival noun or quasi-adjective, takes genitive case の, noun

  1. essential, important, crucial, vital, main.

Variations

Pronunciation Kanji Kana Is Common
肝心 かんじん
肝腎 かんじん

Contained Kanji Breakdown

liver, pluck, nerve
カン きも (8th, N1)
month, moon
つき ゲツ ガツ (1st, N5)
dry, parch, ebb
ひ.る カン ほ.す (6th, N2)
heart, mind, spirit
シン こころ (2nd, N4)