Yes, ail is a Scrabble word!
...and is worth 3 points in Scrabble, and 4 points in Words with Friends
ail
Verb
1. Be ill or unwell
2. Cause bodily suffering to and make sick or indisposed
Noun
1. Aromatic bulb used as seasoning
What Scrabble words can I make with the letters in ail?
2 Letter Words