The phrase "baby sign" refers to a way for babies to communicate before they can talk. It involves using simple hand gestures or signs to express their needs or wants. Full definition
It is important to check if your baby is responding to your gestures before making use of baby sign language. (newkidscenter.com)
Some great activities could be things like music classes, storytelling, one - on - one interactive play time, sensory time and the use of baby sign language. (thespruce.com)
I started using baby sign language with my son and at 18 months now, he still uses many of the signs. (wehavekids.com)