enter: [13] Enter comes ultimately from a Latin preposition and adverb, intrā, which meant ‘inside’ (and was formed from in ‘in’ and the suffix -trā, as in extra). This was taken as the basis of a Latin verb, intrāre ‘enter’, which passed into English via Old French entrer. Of its derivatives, entry [13] has the longer history, going back to a Vulgar Latin *intrāta; entrance [16] is an Old French formation. [enter etymology, enter origin, 英语词源]