adv.副詞在...範圍內;在...裡面I am driving within the speed limit
prep.介系詞中The wolves came out from within the cave
prep.介系詞在...之內The money must be spent within three months.
prep.介系詞在...範圍內The matter is being dealt with within the department.
adv.副詞在內部The solution lies within.