punctual
adj.
c.1400, from Medieval Latin punctualis, from Latin punctus "a pricking" (see point, n.). Originally "having a sharp point; of the nature of a point;" meaning "prompt" first recorded 1670s, from notion of "insisting on fine points." Related: Punctually.
〔李〕[punct;-uala.] a.严守时刻的，准时的； 准确的 ←pung,punct (L pungere,punctum)=to prick 刺
〔蒋〕[punct点，-ual形容词后缀，…的;’着于一点的”→限于一点的→不偏不差的] 精确的，准确的，准时的