The Collaborative International Dictionary of English v.0.48:
malodor \mal*o"dor\, n. An offensive odor. [1913 Webster]WordNet (r) 3.0 (2006):
malodor n 1: a distinctive odor that is offensively unpleasant [syn: malodor, malodour, stench, stink, reek, fetor, foetor, mephitis]