thumb-index

n set of lettered notches cut in theedge of a book, used to identify the position of the varioussections in it (eg the words beginning with a certain letter in a dictionary) 拇指页标（书边切割的缺口, 一般按字母顺序排列, 用以标示各字母所在书中的位置, 如某些字典中的）.

throw sb over, throw sb together, throw sth away, throw sth in, throw sth off, throw sth up, throw up, throw-away, throw-back, throw-in, throw/cast light on, throwback, thru, thrush, thrust, thruster, thud, thug, thuggery, thumb, thumb-nail, thumb-stall, thumb-tack, thumbnail, thumbscrew, thumbtack, thump, thumping (also thundering), thunder, thunder-cloud, thunderbolt, thunderclap, thunderer, thundering, thunderous, thunderously, thunderstorm, thunderstruck, thundery, Thur (also Thurs),