"manufactured goods, goods for sale," Old English waru "article of merchandise," also "protection, guard," hence probably originally "object of care, that which is kept in custody," from Proto-Germanic *waro (source also of Swedish vara, Danish vare, Old Frisian were, Middle Dutch were, Dutch waar, Middle High German, German ware "goods"), from PIE root *wer- (3) "perceive, watch out for."
Usually wares, except in compounds such as hardware, earthenware, etc. Lady ware was a jocular 17c. euphemism for "a woman's private parts" (but sometimes also "male sex organs"), and Middle English had ape-ware "deceptive or false ware; tricks" (mid-13c.).