a worker who moves around and works temporarily in different places
"After his contract ended, he packed up his tools and hit the road as a hobo, seeking seasonal labor wherever it was available."
A wandering homeless person, especially (historical) one illegally travelling by rail or (derogatory) a penniless, unemployed bum.
"The old photograph showed a hobo sleeping on the station platform after his ticket had been torn up by the conductor."
To be a hobo, tramp, bum etc.
"After losing his job and running out of money, he became a complete hobo and spent weeks sleeping in abandoned cars along the highway."