Matching Pairs C22U4LA Voc Not bOnline version What do these idioms mean? Match the columns. by Modern English 1 be a guinea pig 2 beat a dead horse 3 have butterflies in your stomach 4 get off your high horse 5 be in the doghouse 6 clam up 7 be a fish out of water 8 have ants in your pants not fit in, be out of place stop being superior not say anything, perhaps because you feel uncomfortable be the subject of an experiment be anxious or excited to do something be in trouble be nervous waste your time on something