The Collaborative International Dictionary of English v.0.48:
Ach \Ach\, Ache \Ache\, n. [F. ache, L. apium parsley.] A name given to several species of plants; as, smallage, wild celery, parsley. [Obs.] --Holland. [1913 Webster] AchaeanV.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):
ACH Association for Computers and the Humanities (org., USA)