Rare literary or technical noun for hardness or unyielding quality; not used in everyday conversation.
The firmness of this material is very high.
Rare historical or classical term for armor; modern Japanese uses 鎧 (よろい) or 甲冑 (かっちゅう).
In an old document, it says 'to don armor'.
nucleus; backbone; mainstay; key figure · medium-level; mid-level; middle-ranking; midsize · main body (of troops); crack troops; select troops · center field; center fielder · middle-order competitor (in team matches)
steady; sound; reliable; solid
solid; strong; firm
solid; sturdy; durable
adhere firmly to; hold fast to; maintain steadfastly
firm; bullish · strong; steady; sound
strong defense; stout defense
confirmation (Christian rite)
firm and unyielding; rigid
The kanji 堅 originally means 'hard, firm, solid'. As a standalone noun, it is a rare Sino-Japanese reading used in classical or technical contexts.
strong fortress; impregnable castle
stronghold; fortified position
robust; strong; tough
perseverance; steadfast endurance
iron purpose; firm resolve
hard wood
nut
stronghold; impregnable position