knee–high 
/ˈni:ˈhaɪ/ adjective
/ˈni:ˈhaɪ/ adjective : reaching as high as your knees
▪ knee-high boots ▪ The grass is knee-high. ▪ (informal) I haven't seen you since you were knee-high to a grasshopper. [=since you were very young and small]
▪ knee-high boots ▪ The grass is knee-high. ▪ (informal) I haven't seen you since you were knee-high to a grasshopper. [=since you were very young and small]
