late 14c., "walk heavily, stamp," from Middle Low German trampen "to stamp," from Proto-Germanic *tramp- (cf. Danish trampe, Swedish trampa "to tramp, stamp," Gothic ana-trimpan "to press upon"), probably from a variant of the Proto-Germanic source of trap. Related: Tramped; tramping.
"person who wanders about, vagabond," 1660s, from tramp (v). Sense of "steamship which takes cargo wherever it can be traded" (as opposed to one running a regular line) is attested from c.1880. The meaning "promiscuous woman" is from 1922.
To associate with; consort with; hang out: the money it required to train with such/ And I don't train with lawyers
[1871+; probably fr the notion of linking up with or even riding on the train with; perhaps influenced by the prizefighter's close association with those he trains with]