プログレッシブ和英中辞典(第4版)の解説
かとく【家督】
the headship of a family
家督を相続する
inherit 「an estate [a house]
父親は家督を長男に譲った
The father yielded his position as head of the family to his eldest son.
家督相続
succession to (the head position in) a family
家督相続人
〔男〕an heir；〔女〕an heiress