Inseam
Inside Leg
noun
Your crotch and what's below it is called your inseam. It's that line that goes down the inside of your pants. Depending on your variety of English, you might call this your inside leg instead!
This word uses the kun’yomi reading of both kanji. You learned また from the word 股, and you learned した from the word 下 a lonnnng time ago. If you didn't remember either of these, hang your head in shame and look at your またした!
そのジーンズって股下何センチ？
What's the inseam of your jeans in centimeters?
あの巨人の股下は5メートルもある。
That giant's inseam is five meters long.
股下が短すぎるズボンは苦手です。
I'm not a fan of pants that are too short.