He was sitting with his legs spread wide.
Common spelling using 股 (thigh/crotch) with okurigana ぐら.
Alternate kanji spelling; 座 (seat) is used phonetically.
Rarely used kanji form; 胯 is a non-jōyō character for crotch.
Compound of 股 (また, 'crotch, thigh') and ぐら, possibly related to 座 (くら, 'seat') or a mimetic element indicating a straddled space. The exact derivation of ぐら is uncertain.