The sign PEANUT-BUTTER is a combination of PEANUT and BUTTER.
When signed as part of PEANUT-BUTTER the sign BUTTER uses a single movement
instead of a double movement.
To sign peanut, put the tip of your thumb behind your two front teeth then move your hand
forward about 6 inches (which causes the thumb to drag a bit on the bottom
edge of your two front teeth as you move the hand forward). During high speed
signing you don't actually have to touch your teeth -- you just come close
to it. Then do a one-movement version of "butter" by dragging the tips of
the index and middle fingers of an open-H hand across the non-dominant palm.