touchline
noun [ C ] UK uk/ˈtʌtʃ.laɪn/ us/ˈtʌtʃ.laɪn/ (US sideline)
（足球、橄榄球等场地的）边线
one of the two lines that show the position of the long edges of the area in which particular games, such as football, are played
She spends her Saturday afternoons standing on the touchline, watching her boyfriend play rugby. 她每个周六下午总是站在球场边看男朋友打橄榄球。