ay

Short definition from Wiktionary

Interjection

1. 1
   Ah! alas! Expressing anger, alarm, frustration, pain, etc.
2. 2
   Expressing earnestness, surprise, wonder, etc.
3. 3
   Used in ay, ay.
4. 4
   Alternative spelling of aye (“yes”).
5. 5
   New Zealand spelling of eh (question tag).
6. 6
   All right (inter); hooray (inter); cool (inter).

Noun

1. 1
   Alternative spelling of aye (“yes”).
2. 2
   Alternative form of a: the name of the Latin-script letter A/a.
3. 3
   Initialism of academic year.

Adverb

1. 1
   Always; ever; continually; for an indefinite time.