bum

¹ American  

[buhm] / bʌm /

noun

1. a person who avoids work and sponges on others; loafer; idler.

2. a tramp, hobo, or derelict.

   Synonyms:

   vagrant, vagabond

3. 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.

4. Informal. an incompetent person.

5. a drunken orgy; debauch.

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verb (used with object)

bummed, bumming

1. Informal. to borrow without expectation of returning; get for nothing; cadge.

   He's always bumming cigarettes from me.

2. Slang. to ruin or spoil.

   The weather bummed our whole weekend.

verb (used without object)

bummed, bumming

1. to sponge on others for a living; lead an idle or dissolute life.

2. to live as a hobo.

adjective

bummer, bummest

1. Slang. of poor, wretched, or miserable quality; unsatisfactory.

   I figured $300 was a bum deal for a minor repair, but I paid it anyway.

2. Slang. fraudulent or fake.

   He was accused of issuing a bum check for $2920.

3. Slang. disappointing; unpleasant.

4. Slang. erroneous or ill-advised; misleading.

   I think the gauge is giving me a bum readout.

5. Slang. physically disabled, impaired, or injured.

   a bum leg.

verb phrase

1. bum around to travel, wander, or spend one's time aimlessly.

   We bummed around for a couple of hours after work.

idioms

1. on the bum,

   1. living or traveling as or in a manner suggesting that of a hobo or tramp.

   2. in a state of disrepair or disorder.

      The oven is on the bum again.

2. bum (someone) out, to disappoint, upset, or annoy.

   It really bummed me out that she could have helped and didn't.

bum ² American  

[buhm] / bʌm /

noun

Chiefly British Slang.

1. the buttocks; rump.

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bum ¹ British  

/ bʌm /

noun

1. a disreputable loafer or idler

2. a tramp; hobo

3. an irresponsible, unpleasant, or mean person

4. a person who spends a great deal of time on a specified sport

   baseball bum

5. 1. living as a loafer or vagrant

   2. out of repair; broken

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verb

1. (tr) to get by begging; cadge

   to bum a lift

2. to live by begging or as a vagrant or loafer

3. to spend time to no good purpose; loaf; idle

4. slang to disappoint, annoy, or upset someone

adjective

1. (prenominal) of poor quality; useless

2. wrong or inappropriate

   a bum note

bum ² British  

/ bʌm /

noun

1. slang the buttocks or anus

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bum More Idioms  

More idioms and phrases containing bum

• on the blink (bum)

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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

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

I went over and he looked at the prototype, and said, “Why don’t you move this seam over the bum by a centimeter. I think it’ll be more flattering.”

From Los Angeles Times • Mar. 5, 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

"I wouldn't have been worried if I had one bum cheek dragging on the floor. I didn't care at that point, I just wanted to go home," she said.

From BBC • Feb. 23, 2026

This time, since there had been no human casualties during the first outbreak, the Army, the C.D.C., and Hazleton jointly decided to isolate the monkeys—leave them alone and let the virus bum.

From "The Hot Zone" by Richard Preston

Related Words

• bogus
• fake
• fraudulent
• phony
• sham