The Collaborative International Dictionary of English v.0.48:
Oology \O*ol"o*gy\, n. [Gr. w,'o`n an egg + -logy.] The science of eggs in relation to their coloring, size, shape, and number. [1913 Webster]WordNet (r) 3.0 (2006):
oology n 1: the branch of zoology that studies eggs (especially birds' eggs and their size, shape, coloration, and number)