(not of a person) old, aged, antiquated

Alternative spelling of コンデンサ

(electronics) a capacitor / (optics) an optical condenser, such as a lens or mirror / (mechanics, physics) a condenser, a device or unit used to condense vapor into liquid

radio / (slang, dated) broke, having no money; dining and dashing (punning off of 無線 (musen, “wireless”) with the sense of 無銭 (musen, “money-less”)) / radiation (when used as part of a compound)

to exchange

exchange; swap; give-and-take / (mathematics) commutation

the past / ancient times

old

needed, necessary

need, necessity