Definition of "ach"

ach¹

/æt͡ʃ/

noun
plural aches
1. (obsolete) Any of several species of plants, such as smallage, wild celery, parsley.

ach²

/æx/

interjection
1. An expression of annoyance.
  Quotations
  "Ach." Auntie frowned hugely. "That is all nonsense."
  1958, Anthony Burgess, The Enemy in the Blanket (The Malayan Trilogy), published 1972
2. An expression of woe or regret.
3. Alternative form of och