Also found in: Dictionary, Thesaurus, Legal, Encyclopedia.
to enlarge; to inflate; to bulge out. I struck my thumb with a hammer and it swelled up something awful.
1. To become swollen: I put ice on my injured ankle so that it wouldn't swell up.
2. To become filled, as with pride, arrogance, or anger: The new parents swelled up with pride.
3. To rise or surge from an inner source: After I was fired unjustly, rage swelled up within me.