What is "butanethiol"

butyl mercaptan \bu"tyl mer*cap"tan\, n. (Chem.) A volatile liquid, C4H9.SH, having a strong odor like that of a skunk; also called butanethiol. All three isomers, normal, sec-, and tert-butanethiol possess the skunk odor.

n. (context organic chemistry English) The thiol, derived from butane, that is the sulfur equivalent of butanol; it is partly responsible for the smell of skunk

Butanethiol, also known as butyl mercaptan, is a volatile, clear to yellowish liquid with a fetid (extremely foul-smelling) odor, commonly described as " skunk" odor. In fact, butanethiol is structurally similar to several major constituents of a skunk's defensive spray but is not actually present in the spray. The scent of butanethiol is so strong that the human nose can easily detect it in the air at concentrations as low as 10 parts per billion. The threshold level for 1-butanethiol is reported as 1.4 ppb