a small raised spot or swelling on a surface or on the skin
The road was so uneven that the car shook each time it went over a bump.
Mia felt a painful bump on her forehead after she walked into the low doorway.
✦ Originally imitative of a dull hit or swelling, recorded in English since the early 17th century.
to hit or knock into something or someone lightly, often by accident
I’m sorry I bumped your arm when I reached for my bag.
The suitcase bumped against the stairs as she carried it down.
✦ From noun sense ‘a swelling; a blow’, later used as a verb meaning ‘strike with a bump’.
said online to push a message or discussion back to the top of a list
No one has answered my question, so I’ll just type bump to keep the thread active.
The seller wrote bump every morning until someone bought the bike.
✦ Adapted from the idea of ‘bumping’ something upward; common in internet forums since the late 1990s.
a sudden, short increase in amount or level
There was a small bump in sales after the holiday commercial aired.
The team got a morale bump from the coach’s encouraging speech.
✦ Extended metaphorical use of the physical ‘bump’ as something that sticks up, recorded in economics jargon since the mid-20th century.
having an uneven surface with many small raised areas or lumps
The hikers followed a bumpy trail covered with rocks and twisted roots.
She ran her hand over the bumpy bark of the old oak tree.
✦ Formed from the noun "bump" + adjective suffix "-y" in the late 17th century, meaning "full of bumps".
not smooth or easy; filled with difficulties or sudden changes
Their marriage had a bumpy start, but they grew stronger together.
The project is going through a bumpy phase with many unexpected delays.
✦ Extended figurative use of “bumpy” from the idea of a rough road or flight to describe situations that are difficult or unstable (early 20th century).
