Etymology: < Old French aveir, aver, modern French avoir, possession, property, stuff, ‘stock,’ cattle, domestic animals, beasts of burden; lit. ‘having,’ substantive use of aveir , avoir < Latin habēre to have. So Italian avere ‘substance, goods, stocke, chattle’ (Florio); Spanish averes , haveres , plural, ‘goods, wealth, substance’; whence medieval Latin aver , avere , averium , averum , ‘substance, goods,’ and avera , averia , plural (in Anglo-Latin), ‘beasts, cattle,’ singular averum , -ium , sometimes averia , ‘beast,’ averius , affrus , affer , ‘beast of burden, draught-horse.’ English had only the Norman form aveyr , aver , before 1400; the 15th cent. introduced avoir from literary French, from Caxton onward havoir , havor , haviour n. in sense 1. The earlier aver was retained in northern dialect only in a special sense (3).

Etymology: < French avérer, cognate with Provençal averar , Italian avverare < late Latin *advērāre to make true, verify, prove to be true, < ad to (factitive) + vērus true. Sense 2 was the earlier in French.