blastopore(n = noun.animal) - the opening into the archenteron;
is a kind of opening, orifice, porta
is a part of archenteron
Derived forms adjective blastoporal₁, adjective blastoporic₁

   The pore or opening leading into the cavity of invagination, or archenteron.
"[See Illust. of Invagination.]" Balfour. [1913 Webster]