Yes, ad is a Scrabble word!
...and is worth 3 points in Scrabble, and 3 points in Words with Friends
ad
Adverb
1. In the Christian era; used before dates after the supposed year Christ was born
Noun
1. A public promotion of some product or service
Adverb
1. In the Christian era; used before dates after the supposed year Christ was born
Noun
1. A public promotion of some product or service