teratology (n.)

before vowels terat-, word-forming element meaning "marvel, monster," from combining form of Greek teras (genitive teratos) "marvel, sign, wonder, monster," from PIE *kewr-es-, from root *kwer- "to make, form" (source also of Sanskrit krta- "make, do, perform," Lithuanian keras "charm," Old Church Slavonic čaru "charm").

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.