bum
1 Americannoun
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a person who avoids work and sponges on others; loafer; idler.
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a tramp, hobo, or derelict.
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Informal. an enthusiast of a specific sport or recreational activity, especially one who gives it priority over work, family life, etc..
a ski bum; a tennis bum.
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Informal. an incompetent person.
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a drunken orgy; debauch.
verb (used with object)
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Informal. to borrow without expectation of returning; get for nothing; cadge.
He's always bumming cigarettes from me.
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Slang. to ruin or spoil.
The weather bummed our whole weekend.
verb (used without object)
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to sponge on others for a living; lead an idle or dissolute life.
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to live as a hobo.
adjective
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Slang. of poor, wretched, or miserable quality; unsatisfactory.
I figured $300 was a bum deal for a minor repair, but I paid it anyway.
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Slang. fraudulent or fake.
He was accused of issuing a bum check for $2920.
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Slang. disappointing; unpleasant.
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Slang. erroneous or ill-advised; misleading.
I think the gauge is giving me a bum readout.
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Slang. physically disabled, impaired, or injured.
a bum leg.
verb phrase
idioms
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on the bum,
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living or traveling as or in a manner suggesting that of a hobo or tramp.
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in a state of disrepair or disorder.
The oven is on the bum again.
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bum (someone) out, to disappoint, upset, or annoy.
It really bummed me out that she could have helped and didn't.
noun
noun
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a disreputable loafer or idler
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a tramp; hobo
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an irresponsible, unpleasant, or mean person
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a person who spends a great deal of time on a specified sport
baseball bum
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living as a loafer or vagrant
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out of repair; broken
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verb
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(tr) to get by begging; cadge
to bum a lift
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to live by begging or as a vagrant or loafer
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to spend time to no good purpose; loaf; idle
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slang to disappoint, annoy, or upset someone
adjective
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(prenominal) of poor quality; useless
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wrong or inappropriate
a bum note
noun
Etymology
Origin of bum1
An Americanism first recorded in 1860–65; perhaps a shortening of or back formation from bummer 1; adjective senses of unclear relation to sense “loafer” and perhaps of distinct origin
Origin of bum2
First recorded in 1350–1400; Middle English bom; of uncertain origin
Explanation
Your bum is your bottom. This word can also be used to refer to a vagrant, although it's generally considered offensive or insensitive. Bum is a name sometimes given to a beggar or vagrant: someone who tries to bum change from you. This word can also be used as a general insult, as in "The Yankees are bums!" (if you're a Red Sox fan) or "The Red Sox are bums!" (if you're a Yankees fan). A false accusation is a bum rap. As a verb, bum is a term for lazing around, as in, "I didn't have any homework this afternoon, so I just bummed around and played video games."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Advancements that seek to end the friction of reality — the freak occurrences, edge cases and bum luck of a given day — ultimately sap the world of excitement and color.
From Salon • Apr. 13, 2026
But sometimes you can’t, like when you ask a chatbot a factual question and get a bum steer.
From The Wall Street Journal • Feb. 25, 2026
And while I don’t know if there’s a world in which I’d wear that stuff, I would like to feel confident about my bum.
From Slate • Feb. 22, 2026
Do you agree, and if so does that bum you out?
From Los Angeles Times • Dec. 18, 2025
“As I mentioned not too long ago, this is my house. Ain’t no bum knee can stop me from going wherever I wanna go inside it.”
From "Fast Pitch" by Nic Stone
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.