English
forestaff
From fore- + staff.
Proto-Indo-European *per- ‘before, formerly’
Proto-Germanic *fura- ‘before, in front of, for’
Proto-West Germanic *forē- ‘before, in front of, fore-, pre-’
English fore-
Proto-Indo-European *stebʰ- ‘to stand still’
…
Proto-Germanic *stabaz ‘staff’
Proto-West Germanic *stab
Old English stæf ‘letter of the alphabet’
Middle English staf ‘a staff used to support one's movement’
English staff
Today it means
noun An instrument formerly used at sea for taking the altitudes of heavenly bodies, later replaced by the sextant.
Language periods are conventional ranges, not dates for this word.
Etymograph / forestaff