entomology (n.) Look up entomology at Dictionary.com
1766, from French entomologie (1764), coined from Greek entomon "insect" + -logia "study of" (see -logy). Entomon is neuter of entomos "having a notch or cut (at the waist)," from en "in" (see en- (2)) + temnein "to cut" (see tome).

So called by Aristotle in reference to the segmented division of insect bodies. Compare insect. Related: Entomological. Hybrid insectology (1766, from French insectologie, 1744) is not much used.
I have given the name insectology to that part of natural history which has insects for its object; that of entomology ... would undoubtedly have been more suitable ... but its barbarous sound terryfy'd me. [Charles Bonnet's English translation of his "Contemplation de la nature," 1766]