Teach your baby the sign for the word big in baby sign language with the following description and video.
Form a modified C with both hands. Hold the hands in front of the body with the tips of the index fingers and thumbs touching. Pull the hands apart.
Acredolo, Linda & Susan Goodwyn. 2009. Baby signs: How to talk with your baby before your baby can talk, 3rd edn. New York: McGraw Hill.