To lollygag is to be slow or idle or lazy. You might say to your dawdling friends, "Don't lollygag! We'll miss our bus!"
You lollygag when you take you own sweet time walking to your piano teacher's house, and you also lollygag when you lounge lazily in a hammock under a tree. The word lollygag is an American invention, a slang term that's sometimes spelled lallygag and may stem from the dialectical "tongue" meaning of lolly.