1. [n]  the formal act of liberating someone
2. [n]  a warrant granting release from punishment for an offense
3. [n]  a period during which offenders are exempt from punishment
4. [v]  grant a pardon to (a group of people)

AMNESTY is a 7 letter word that starts with A.

1. \Am"nes*ty\, n. [L. amnestia, Gr. ?, a forgetting, fr. ?
   forgotten, forgetful; 'a priv. + ? to remember: cf. F.
   amnistie, earlier amnestie. See {Mean}, v.]
   1. Forgetfulness; cessation of remembrance of wrong;
      oblivion.
   2. An act of the sovereign power granting oblivion, or a
      general pardon, for a past offense, as to subjects
      concerned in an insurrection.
   

2. \Am"nes*ty\, v. t. [imp. p. p. {Amnestied}; p. pr. & vb.
   n. {Amnestying}.]
   To grant amnesty to.