frequent: [16] Frequent comes from Latin frequēns, which meant ‘crowded’ as well as ‘regularly repeated’ (it is not known what the origins of frequēns were, although it may be related to Latin farcīre ‘stuff’, source of English farce). The sense ‘crowded’ was carried over into English along with ‘regularly repeated’, but it had virtually died out by the end of the 18th century. The verb frequent [15] goes back to Latin frequentāre ‘visit frequently or regularly’. [frequent etymology, frequent origin, 英语词源]