1.
standing on tiptoe; tiptoeing
The act or posture of raising oneself up on the tips of the toes, either to reach something high or to walk quietly.
Literally "tip-of-toe standing," from つま先 (tiptoe, toe tip) and 立ち (standing). Used both for the physical action of raising oneself on tiptoe to reach something and for the quiet, careful walking associated with tiptoeing.
Often written in hiragana or mixed script (つま先立ち) rather than full kanji (爪先立ち). The verb form つま先立ちする is also common.