A pillow is a cushioned support for the head and neck during sleep or relaxation. There are various synonyms for the word "pillow" that you can use in different contexts. Some of the common synonyms for pillow include cushion, headrest, bolster, pad, and sleeping pad. A cushion is a soft bag filled with air or foam that is used for sitting or resting. A headrest is a support that is used for resting the head. A bolster is a long pillow that is used to support the back or legs. A pad is a soft cushion that is used to protect or cushion something. Lastly, a sleeping pad is a mat or cushion that is placed underneath a sleeping bag for extra comfort.