Definition of worm noun from the Oxford Advanced American Dictionary

worm

noun
/wərm/
 
 
1 [countable] a long, thin creature with no bones or legs, that lives in soilbirds looking for worms see also earthworm, lugworm2 worms [plural] long, thin creatures that live inside the bodies of humans or animals and can cause illnessThe dog has worms. see also hookworm, tapeworm3 [countable] the young form of an insect when it looks like a short wormThis apple is full of worms. see also glowworm, silkworm, woodworm4 [countable] (computing) a computer program that is a type of virus and that spreads across a network by copying itself5 [countable, usually singular] (informal, disapproving) a person you do not like or respect, especially because they have a weak character and do not behave well toward other peopleIDIOMS

a can of worms

(informal) if you open up a can of worms, you start doing something that will cause a lot of problems and be very difficulta can of worms

the early bird catches the worm

(saying) a person who takes the opportunity to do something before other people will have an advantage over themthe early bird catches the worm

the worm will turn

(saying) a person who is normally quiet and does not complain will protest when the situation becomes too hard to bearthe worm will turn