(n.) A helper; a companion; specifically, a wife.

acolyte adjutant agent aid aide aide-de-camp aider assistant attendant auxiliary best man better half coadjutant coadjutor coadjutress coadjutrix common-law wife concubine deputy executive officer feme feme covert goodwife goody help helper helpmeet lady lieutenant married woman matron old lady old woman paranymph paraprofessional rib second servant sideman squaw supporting actor supporting instrumentalist wedded wife wife woman