noun.buttocks

• fell down on his bum

adjective.of poor quality or nature

• bum advice
• writing a bum check

adjective.not valid or deserved

• a bum trip
• has a bum knee

adjective.not pleasant or enjoyable

verb.loaf

• bummed around the house all day
• bum a cigarette

verb.to spend time unemployed and often wandering —often used with around

verb.to obtain by asking or begging: cadge

noun.someone who lives off others and avoids work: sponge

• He's a lazy bum.
• The fans called the umpire a bum.

noun.someone who performs a function poorly

• a beach bum
• ski bums

noun.someone whose time is devoted to a recreational activity

• bums sleeping on park benches

noun.a drinking spree: bender

• a 2-day bum

verb.disappoint, depress —usually used with out