"fetus in utero at an early stage of development," mid-14c., from Medieval Latin embryo, properly embryon, from Greek embryon "a young one," in Homer, "young animal," later, "fruit of the womb," literally "that which grows," from assimilated form of en "in" (from PIE root *en "in") + bryein "to swell, be full."
word-forming element meaning "a speaking, discourse, treatise, doctrine, theory, science," from Greek -logia (often via French -logie or Medieval Latin -logia), from -log-, combining form of legein "to speak, tell;" thus, "the character or deportment of one who speaks or treats of (a certain subject);" from PIE root *leg- (1) "to collect, gather," with derivatives meaning "to speak (to 'pick out words')." Often via Medieval Latin -logia, French -logie. In philology "love of learning; love of words or discourse," apology, doxology, analogy, trilogy, etc., Greek logos "word, speech, statement, discourse" is directly concerned.
<a href="https://www.etymonline.com/word/embryology">Etymology of embryology by etymonline</a>
Harper, D. (n.d.). Etymology of embryology. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/embryology