footfault是什么意思？

footfault

英['fʊtfɔ:lt] 美['fʊtfɔlt]

• n. 脚步犯规（发球时踩线或双脚离地），踩线；

英英词典释义

• Noun
  1. a fault that occurs when the server in tennis fails to keep both feet behind the baseline