3 letters:
cup, pup, sup, yup

5 letters:
getup, krupp, letup, pinup, setup, shtup

6 letters:
backup, blowup, burnup, cockup, dustup, eggcup, eyecup, get-up, holdup, hookup, kickup, lay-up, lineup, linkup, lockup, makeup, markup, mix-up, pickup, pileup, pin-up, pop-up, pushup, put-up, run-up, selkup, sendup, set-up, sit-up, slipup, teacup, tie-up, tip-up, tittup, tossup, turnup, washup, wickup, windup

7 letters:
back-up, bang-up, beat-up, breakup, brushup, buildup, bust-up, call-up, checkup, chin-up, cleanup, closeup, cock-up, coverup, dial-up, foul-up, goldcup, grownup, hang-up, high-up, kingcup, lash-up, line-up, made-up, make-up, mess-up, mock-up, nosh-up, paid-up, pent-up, pick-up, piss-up, pull-up, push-up, rave-up, roll-up, roundup, shakeup, slap-up, slip-up, speedup, standup, startup, step-up, stickup, take-up, toss-up, tune-up, used-up, walk-up, warm-up, wickiup, wind-up

8 letters:
balls-up, belly-up, blown-up, booze-up, built-up, close-up, cover-up, crack-up, dried-up, flare-up, followup, frame-up, grown-up, heads-up, mixed-up, paste-up, press-up, punch-up, seven-up, shake-up, shape-up, smash-up, snarl-up, stand-up, start-up, stuck-up, whitecup, write-up

9 letters:
beaten-up, beefed-up, bottom-up, buttercup, change-up, follow-up, fucked-up, heaped-up, higher-up, hopped-up, jumped-up, marked-up, pumped-up, rolled-up, runner-up, washed-up

10 letters:
churned-up, dressed-up, pick-me-up, stopped-up, trumped-up, washing-up

11 letters:
puckered-up

14 letters:
johnny-jump-up

3 letters:
cub, dub, hub, nub, rub, pub, tub, sub

4 letters:
snub, club, grub, drub, stub

5 letters:
shrub, scrub

8 letters:
subshrub