1) An offensive smell or odor 2) Awful smell 3) Bad aroma 4) Bad odor 5) Big stink 6) Cause for nose-holding 7) Dumpster emanation 8) Extremely offensive odour 9) Fetor 10) Foetor 11) Foul fetor 12) Foul odor 13) Foul quality 14) Hardly an olfactory delight 15) Horrid smell 16) It may be foul 17) It may make the nose wrinkle 1) Bads 2) Fetor 3) Foetor 4) Malodor 5) Malodour 6) Miasma 7) Niff 8) Odor 9) Pong 10) Reek 11) Smell 12) Stink 
• (v. i.) An ill smell; an offensive odor; a stink. • (v. i.) A smell; an odor. • (v. t.) To stanch. • (n.) To cause to emit a disagreeable odor; to cause to stink.
very bad smell
Stench noun [ Anglo-Saxon stenc a strong smell, from stincan . See Stink , intransitive verb ] 1. A smell; an odor. [ Obsolete] « Clouds of savory stench involve the sky.» Dryden. 2. An ill smell; an offensive ...Stench transitive verb To stanch. [ Obsolete] Harvey. 
an offensive smell or odor; stink. · a foul quality.
a distinctive odor that is offensively unpleasant