-logy Look up -logy at Dictionary.com
word-forming element meaning "a speaking, discourse, treatise, doctrine, theory, science," from Greek -logia (often via French -logie or Medieval Latin -logia), from root of legein "to speak;" thus, "the character or deportment of one who speaks or treats of (a certain subject);" see lecture (n.). Often via Medieval Latin -logia, French -logie.