Definitions

1. adjective

Having the form of a placode; relating to or resembling a placode.

“The placoidal tissue in the embryo is crucial for its development.”

2. noun

A small, rounded or oval plate or area of ectoderm in the early embryo of a vertebrate, from which a sensory organ or other structure develops.

“The placoidals on the embryo eventually gave rise to the eyes and ears of the newborn.”