\Mer*cap"tan\, n. [F., fr. NL. mercurius mercury + L.
captans, p. pr. of captare to seize, v. intens. fr. capere.]
(Chem.)
Any one of series of compounds, hydrosulphides of alcohol
radicals, in composition resembling the alcohols, but
containing sulphur in place of oxygen, and hence called also
the {sulphur alcohols}. In general, they are colorless
liquids having a strong, repulsive, garlic odor. The name is
specifically applied to ethyl mercaptan, {C2H5SH}. So called
from its avidity for mercury, and other metals.