To swell is to expand or grow larger. If your brother's face started to swell after he ate lobster for the first time, you'd probably guess that he's allergic to shellfish.

You can use the word swell to describe what happens to an injured body part, like a black eye that swells up, or in a figurative way, to describe a feeling of fullness, like when your heart swells with pride at your sister's big music performance. In the 1930s, swell became a popular slang term meaning great or excellent. But it also can describe a wealthy, elegant person, like a group of swells at a fancy restaurant.

Definitions of swell
  1. verb
    increase in size, magnitude, number, or intensity
    “The music swelled to a crescendo”
    see moresee less
    type of:
    become bigger or greater in amount
  2. verb
    expand abnormally
    synonyms: intumesce, swell up, tumefy, tumesce
    see moresee less
    show 5 types...
    hide 5 types...
    swell from or as if from internal pressure
    belly, belly out
    swell out or bulge out
    blow up, puff, puff out, puff up
    to swell or cause to enlarge, "Her faced puffed up from the drugs"
    become bloated or swollen or puff up
    blister, vesicate
    get blistered
    type of:
    become larger in size or volume or quantity
  3. verb
    cause to become swollen
    “The water swells the wood”
    see moresee less
    show 4 types...
    hide 4 types...
    bulge, bulk
    cause to bulge or swell outwards
    cause to become very swollen
    make bloated or swollen
    cause to expand as if by internal pressure
    type of:
    cause to grow or develop
  4. noun
    a rounded elevation (especially one on an ocean floor)
    see moresee less
    type of:
    elevation, eminence, natural elevation
    a raised or elevated geological formation
  5. noun
    a crescendo followed by a decrescendo
    see moresee less
    type of:
    (music) a gradual increase in loudness
  6. verb
    come up (as of feelings and thoughts, or other ephemeral things)
    “Smoke swelled from it”
    synonyms: well up
    see moresee less
    type of:
    arise, develop, grow, originate, rise, spring up, uprise
    come into existence; take on form or shape
  7. verb
    become filled with pride, arrogance, or anger
    “The mother was swelling with importance when she spoke of her son”
    synonyms: puff up
    see moresee less
    type of:
    act, behave, do
    behave in a certain manner; show a certain behavior; conduct or comport oneself
  8. verb
    come up, as of a liquid
    synonyms: well
    see moresee less
    type of:
    come up, rise, rise up, surface
    come to the surface
  9. noun
    the undulating movement of the surface of the open sea
    synonyms: crestless wave
    see moresee less
    ground swell, heavy swell
    a broad and deep undulation of the ocean
    type of:
    moving ridge, wave
    one of a series of ridges that moves across the surface of a liquid (especially across a large body of water)
  10. adjective
    very good
    synonyms: bang-up, bully, corking, cracking, dandy, great, groovy, keen, neat, nifty, not bad, peachy, slap-up, smashing
    having desirable or positive qualities especially those suitable for a thing specified
  11. noun
    a man who is much concerned with his dress and appearance
    synonyms: beau, clotheshorse, dandy, dude, fashion plate, fop, gallant, sheik
    see moresee less
    George Bryan Brummell
    English dandy who was a fashion leader during the Regency (1778-1840)
    cockscomb, coxcomb
    a conceited dandy who is overly impressed by his own accomplishments
    a British dandy in the 18th century who affected Continental mannerisms
    type of:
    adult male, man
    an adult person who is male (as opposed to a woman)
Word Family

Test prep from the experts

Boost your test score with programs developed by’s experts.

  • Proven methods: Learn faster, remember longer with our scientific approach.
  • Personalized plan: We customize your experience to maximize your learning.
  • Strategic studying: Focus on the words that are most crucial for success.


  • Number of words: 500+
  • Duration: 8 weeks or less
  • Time: 1 hour / week


  • Number of words: 500+
  • Duration: 10 weeks or less
  • Time: 1 hour / week


  • Number of words: 700+
  • Duration: 10 weeks
  • Time: 1 hour / week