From Old English 'crūdan' (to press, push) — the noun for a gathered group came from the verb for being pressed together.
A large number of people gathered together.
From Old English 'crūdan' meaning 'to press, push, hasten,' from Proto-Germanic *krūdaną. The noun developed from the verb — a crowd is people being pressed together. The original emphasis was on the pushing, not the group. Key