笑 is a kanji（Chinese character）. The onyomi（sound from Chinese）is ショウshoo［syo：］ and kunyomi（Japanese translation） is わら（う）<to laugh>, わら（い）<laughing>,え（む）<to smile>, え（み）<smiling>. There is no full word here. 笑 is used like a symbol/sign/mark of laughing. If we dare to pronounce this, we can say わらい. Actually some people use "w" instead of （笑）. It comes from the first alphabet of "warai わらい". As for me, I use （^^）,（^^）/,（^-^） instead of them.

It's like "lol" or "XD" in English. I hope you got it.