This is how you sign Foster in American Sign Language.
Learn how to sign "foster" in American Sign Language(ASL). Create a 'K' with both hands by forming fists and extending your index and middle fingers at a 90-degree angle to your palm, with thumbs resting at the vertex of the index and middle fingers. Place the right "K" hand on top of the left "K" hand. While keeping them together, move them forward, down, back, and up again in a circular movement.