Synonyms for Swell:

adj.

agreeable (adjective)
dandy.
all right (adjective)
good.
swell (adjective)
fine, nifty, desirable, excellent, neat, keen.

n.

spurt, explosion, leap, upsurge, upswing, surge, growth, jump. raise, add to, multiply, step up, go through the roof, soar, escalate, go up. cushdy, select, singular, ace, plum. go off, deafen, fade, ring, rise, reverberate, deepen, echo. cap, flood tide, high water, high tide, billow, high-water mark, breaker, backwash, crest, low tide. bowl, bulge, coil, circle, balloon, cone, band, ball, bubble, crescent. wax and wane, outgrow, supersize, double, mature. nurse, possess, give up to, tingle, experience, walk away with, feel, burn, overflow, let yourself go. scale up, bulk out, maximize. fashion plate (noun)
clotheshorse.
first-rate (noun)
excellent, fine, desirable.
fop (noun)
blood, beau, dude, fop, clotheshorse, dandy, beauty, socialite, cavalier, peacock, blade, gallant.
swell (noun)
gallant, great, slap-up, sheik, crestless wave, intumesce, peachy, corking, dandy, dude, well, bang up, fashion plate, growth, smashing, beau, not bad, billow, tumefy, neat, bully, cracking, fop, swell up, nifty, surge, good, keen, rise, puff up, groovy, well up, clotheshorse.

v.

abound (verb)
overflow.
amplify (verb)
magnify, deepen, lengthen, stretch, widen, raise, develop, inflate.
expand (verb)
distend, fatten, burgeon, widen, engorge, increment, expand, extend, augment, grow, dilate, enlarge, lengthen, thicken, broaden, develop, increase, inflate, spread, magnify, amplify, stretch.
social (verb)
puff up.
swell (verb)
dilate, extend, distend, augment, enlarge, increase, bulge, fatten, well up, tumefy, balloon, puff up, amplify, grow, expand, add to.

Other synonyms:

fade, maximize, scale up, deafen, bulk out, surge, upsurge. echo, escalate, excellent, deepen, supersize, reverberate, upswing. ring, soar, go off. multiply, outgrow, fine. growth. go up, rise. mature. double. bang-up
bang up.
billow
puff up.
expand
expand.
open up
widen.
Other relevant words:
fine, peachy, go up, bulge, neat, puff up, balloon, surge, rise, slap-up, billow, bully, keen, great, nifty.

Usage examples for swell

  1. You are a swell – The Lion's Share by E. Arnold Bennett
  2. The words, almost like an order, made Neale's heart swell for a moment. – The U.P. Trail by Zane Grey
  3. A swell chance for you to spend part or all of your vacation with Professor Brierly and your friend, Matthews. – Death Points a Finger by Will Levinrew