English
guardroom
From guard + room.
Proto-Germanic *wardāną ‘to guard, protect’
…
Early Medieval Latin wardō
Old French guarder ‘to protect, guard’
Old French guarde ‘protection; guard’
Middle English garde ‘guardianship’
English guard
Proto-Indo-European *(H)rewH- ‘to root’
Proto-Germanic *rūmą
Proto-West Germanic *rūm
Old English rūm ‘room’
Middle English roum ‘room’
English room
Today it means
noun A room used by soldiers when on guard.
Language periods are conventional ranges, not dates for this word.
Etymograph / guardroom