(ˈ) ̷ ̷ˈ ̷ ̷trəs noun
also an·es·trum -rəm ; or an·oes·trus -rəs ; or an·oes·trum -rəm
( plural anes·tri -ˌstrī ; or anes·tra -_strə)
Etymology: New Latin, from an- + estrus, estrum, oestrus, or oestrum
: the period of sexual quiescence between two periods of sexual activity in cyclically breeding mammals — compare estrus