1
standing on tiptoe and stretching one's back to make oneself taller;stretching oneself
彼は背伸びをして失敗した。
He bit off more than he could chew.
2
overreaching oneself;overstretching oneself;trying to do something beyond one's ability;pushing to the limit
Other forms
背延び 【せのび】 (rarely used kanji form) · 背のび 【せのび】 (search-only kanji form)