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) 拇指頁標（書邊切割的缺口, 一般按字母順序排列, 用以標示各字母所在書中的位置, 如某些字典中的）.
thumb-nail
n nail at the tip of the thumb 拇指的指甲. adj [attrib 作定語] briefly written 文字簡潔的: a thumb-nail sketch/portrait/description of sb/sth 對某人[某事物]的簡略描述.
thumbscrew
n former instrument of torture that squeezed the thumb 拇指夾（舊時的刑具）.
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) 拇指頁標（書邊切割的缺口, 一般按字母順序排列, 用以標示各字母所在書中的位置, 如某些字典中的）.
thumb-nail
n nail at the tip of the thumb 拇指的指甲. adj [attrib 作定語] briefly written 文字簡潔的: a thumb-nail sketch/portrait/description of sb/sth 對某人[某事物]的簡略描述.
thumbscrew
n former instrument of torture that squeezed the thumb 拇指夾（舊時的刑具）.
thumb-stall
n sheath to cover an injured thumb 拇指套（保護受傷拇指的）.
thumb-tack
n (US) = drawing-pin (drawing).