Use the word slug to mean "bullet," "slimy, land-dwelling mollusk," or "super lazy person." If your mom finds you on the couch as often as she finds slugs in her garden, she'll call you a slug too.
When it's a verb, slug means "hit," so you might say, "That bully's always threatening to slug me." As a noun, slug can also mean "a blow," or "a gulp." But if your little brother is barefoot outside and suddenly screams, "Yuck, I stepped on a slug!" he is most likely talking about the squishy invertebrate that leaves a trail of slime behind it.