4 letters:
down, gown, lown, noun, town

5 letters:
brown, clown, crown, drown, frown

6 letters:
adnoun, around, godown, motown, renown, uptown

7 letters:
buydown, embrown, go down, hoedown, letdown, lowdown, midtown, miltown, rubdown, rundown, sundown

8 letters:
backdown, beantown, bed down, bog down, bow down, comedown, cut down, die down, downtown, drawdown, freetown, get down, gun down, hometown, jot down, kip down, lay down, let down, lie down, lockdown, lookdown, low-down, markdown, meltdown, mow down, peg down, pin down, put-down, put down, ram down, rub down, run-down, run down, sag down, set down, showdown, shutdown, sit-down, sit down, slowdown, takedown, tea gown, tie down, top-down, turndown, yorktown

9 letters:
allentown, back down, ball gown, bear down, beat down, belt down, boil down, bolt down, boom town, breakdown, bunk down, burn down, call down, calm down, cape town, cast down, chinatown, chop down, clampdown, closedown, come down, cool down, countdown, crackdown, crosstown, dash down, deep down, doss down, down town, drag down, drop down, eiderdown, fall down, flag down, flap down, hand-down, hand down, hold down, hose down, hunt down, jamestown, keep down, kick down, kingstown, knockdown, live down, load down, mark down, mass noun, melt down, nail down, nightgown, pare down, pipe down, play down, pour down, pull down, push down, rain down, roll down, runaround, send down, shakedown, shut down, skip town, slim down, slow down, southdown, spelldown, standdown, step-down, step down, take down, talk down, tamp down, tear down, tone down, touchdown, trim down, turn down, vote down, wash down, watertown, wear down, wolf down

10 letters:
bowed down, break down, bridgetown, bring down, brush down, choke down, clamp down, climb-down, climb down, close down, count down, count noun, crack down, dark-brown, deep brown, dress down, drink down, fight down, flush down, georgetown, ghost town, grind down, hagerstown, half crown, hands down, knock-down, knock down, morgantown, morristown, place down, plank down, playground, plump down, plunk down, press down, quiet down, right-down, round down, scale down, shantytown, shire town, shoot-down, shoot down, shout down, sleek down, slick down, slide down, small town, splashdown, split down, stamp down, stare down, strip down, swill down, toned down, touch down, track down, tumbledown, water down, weigh down, write-down, write down, youngstown

11 letters:
batten down, bridal gown, broken-down, buckle down, button-down, common noun, cooperstown, county town, dinner gown, freeze down, geneva gown, george town, handed-down, hunker down, light brown, loaded down, market town, mummy-brown, narrow down, olive brown, out-of-town, proper noun, rattle down, remain down, settle down, shower down, simmer down, sluice down, snuff-brown, sponge down, steady down, strike down, thistledown, tumble-down, upside-down, verbal noun, weight down

12 letters:
bargain down, cascade down, dwindle down, evening gown, hand-me-down, jacket crown, knuckle down, letting down, nero's crown, ratchet down, tearing down, triple crown, wedding gown, weighed down, whittle down, yellow-brown

13 letters:
academic gown, buttoned-down, caramel brown, charlottetown, chukker-brown, dressing-down, dressing down, dressing gown, grayish brown, hunkered down, optical crown, reddish-brown, reddish brown, stepping down, stripped-down, surgical gown, vandyke brown

14 letters:
hampshire down, man-about-town

15 letters:
take lying down, yellowish brown

16 letters:
talk of the town

17 letters:
nervous breakdown

19 letters:
jumping up and down

20 letters:
counsel to the crown