If you stretch out a part of your body, you hold it out straight. He was about to stretch out his hand to grab me
thrust or extend out; "He held out his hand"; "point a finger"; "extend a hand"; "the bee exserted its sting"
If you stretch out or stretch yourself out, you lie with your legs and body in a straight line. The jacuzzi was too small to stretch out in Moira stretched herself out on the lower bench
extend one's body or limbs; "Let's stretch for a minute--we've been sitting here for over 3 hours"