noun
stealthy steps; tiptoeing
Walking quietly so as not to be noticed. Often used in set phrases like 差し足で歩く or 差し足で近づく.
泥棒は差し足で家の中に入った。
The burglar entered the house with stealthy steps.
彼は差し足で忍び寄り、友達を驚かせた。
He crept up on tiptoe and surprised his friend.
noun
final spurt to overtake the leader (horse racing)
Specialized horse-racing term for a late burst of speed just before the finish line to pass the leading horse.
あの馬は最後の差し足が鋭い。
That horse has a sharp final spurt.
差し足で先頭をかわして優勝した。
It overtook the leader with a late spurt and won.
抜き足 is often paired with 差し足 in the phrase 抜き足差し足, meaning 'sneaking' or 'on tiptoe'. 抜き足 refers to lifting the foot quietly, while 差し足 refers to placing it down quietly.
Compound of 差し (sashi, continuative form of 差す 'to extend, put forward') + 足 (ashi, 'foot, step'). Literally 'extending step'.