Lewis Short
(verb) : aestīvo, āvi, ātum, 1, aestivus
* To spend or pass the summer in a place (like hiemo, to pass the winter; so in Gr. θερίζω and χειμάζω), Varr. R. R. 2, 1: mihi greges in Apuliā hibernabant, qui in Reatinibus montibus aestivabant,id. ib. 2, 2: intra saepem aestivant pastores opacam,Plin. 12, 5, 11, § 22; Suet. Galb. 4; id. Vesp. 24; Stat. S. 4, 4, 22.
Charlton T. Lewis, Charles Short, A Latin Dictionary