カ, くわ.える, くわ.わる
add, addition, increase, join, include, Canada
JLPT3 G4 S5 F130
A variant of 可 (bend/cup a hand about the mouth to amplify the voice in shouting), with *add*, *append* and *increase* being associated meanings (← add a hand atop the mouth to increase the volume of one's voice). Also, *join* (in) and *inflict* (← join in something inflicting damage/injury).
[Full Kanji Etymology List]