[or.ni.thol.o.gy] n, pl -gies [NL ornithologia, fr. ornith- + -logia -logy] (1678) 1: a branch of zoology dealing with birds
2: a treatise on ornithology -- or.ni.tho.log.i.cal also or.ni.tho.log.ic adj -- or.ni.tho.log.i.cal.ly adv -- or.ni.thol.o.gist n