What does acrid mean?
The definition of acrid
Ac”rid, a.
Etym: [L. acer sharp; prob. assimilated in form to acid. See Eager.]

1 Sharp and harsh, or bitter and not, to the taste; pungent; as, acrid salts.
2 Causing heat and irritation; corrosive; as, acrid secretions.
3 Caustic; bitter; bitterly irritating; as, acrid temper, mind, writing. Acrid poison, a poison which irritates, corrodes, or burns the parts to which it is applied.