嫡
チャク, テキ
legitimate wife, direct descent (non-bastard)
JLPT1 G7 S14 F2130
As per
啇
# (variant of
啻
) (unify) +
女
woman → one's (legal) wife, part of the spousal unit → (legitimate) *heir*; (legitimate) *child*.
[Full Kanji Etymology List]