trailer (n.)

1580s, "hound or huntsman that follows a trail," agent noun from trail (v.). From 1610s as "Something that trails." From 1890 as "vehicle pulled by another;" originally a small carriage drawn along by a bicycle. Meaning "preview of a coming movie" first attested 1928. Trailer park "mobile home community" recorded by 1936. Trailer trash in use by 1986.