proestrus

pro·es·trus

noun \-ˈes-trəs\

Definition of PROESTRUS

: a preparatory period immediately preceding estrus and characterized by growth of graafian follicles, increased estrogenic activity, and alteration of uterine and vaginal mucosa

Variants of PROESTRUS

pro·es·trus or pro·es·trum \-ˈes-trəm\ or chiefly British pro–oes·trus or pro–oes·trum \-ˈēs-\