Definition of greasers:
(n) :
(slang) A mechanic.
(n) :
(slang) A biker, a tough.
(n) :
(slang) A rocker or metalhead, especially one who listens to 1950s rock and roll or 1980s thrash metal.
(n) :
Someone or something that greases (applies grease).
(n) :
(aviation, slang) A very soft landing.
(n) :
(US, offensive, ethnic slur) A Latin American, especially a Mexican.