crack up

1 to declare enthusiastic approval of that sports car isn't all it's cracked up to be Synonyms accredit, applaud, cheer, acclaim, hail, laud, praise, salute, toutRelated Words bravo, clap, rise (to); ballyhoo; approve, commend, endorse (also indorse), favor, recommend, root (for), support; celebrate, emblazon, eulogize, extol (also extoll), glorify, magnify, sing; adulate, belaud, flatter, overpraise; deify, idolizeNear Antonyms belittle, discommend, disparage, put down; blame, censure, reprehend, reprobate; admonish, chide, criticize, rebuke, reprimand, reproach, reprove; castigate, excoriate, keelhaul, lambaste (or lambast), skewer, slag [chiefly British], vilifyAntonyms knock, pan, slam

2 to praise or publicize lavishly and often excessively the movie is being cracked up as the blockbuster of the summer Synonyms ballyhoo, blow up, tout, cry up, glorify, trumpet, tub-thumpRelated Words acclaim, applaud, extol (also extoll), laud, magnify; commend, compliment, eulogize; advance, advertise, announce, blare, blaze, blazon, boost, herald, offer, plug, promote, publicize; assert, aver, claim, declare, lay down, make out, proclaim, pronounce

3 to show mirth with an explosive vocal sound try not to crack up at your own punch lines—it's funnier if you keep a straight face Synonyms break up, cackle, chortle, chuckle, laugh, giggle, hee-haw, roar, scream, snicker, titter, twitterRelated Words grin, smileNear Antonyms bawl, blubber, cry, sob, weep; howl, scream, squall, wail, yowl; bleat, pule, whimper, whine; sniffle, snivel; groan, moan, sigh