The term 'POPULAR SHAVER' can be solved by the four-letter word ATRA. ATRA is a brand of electric shavers manufactured by Panasonic Corporation. The ATRA series of shavers are known for their high quality and popularity among consumers. They feature a unique design that allows for a close shave with minimal irritation. The ATRA series of shavers also come with a variety of attachments, making them a versatile choice for any grooming need.