The Collaborative International Dictionary of English v.0.48:
Sociology \So`ci*ol"o*gy\, n. [L. socius a companion + -logy.] That branch of philosophy which treats of the constitution, phenomena, and development of human society; social science. --H. Spencer. [1913 Webster]WordNet (r) 3.0 (2006):
sociology n 1: the study and classification of human societies