D defs.my
Entry 4 senses · 2 variants Webster, 1913

Alter

/ôl'-tẽr/ · Al·ter · IPA /ˈɔl.təɹ/
01 v. t. To make otherwise; to change in some respect, either partially or wholly; to vary; to modify.
imp. & p. p. Altered; p. pr. & vb. n. Altering
  1. 1.
    To make otherwise; to change in some respect, either partially or wholly; to vary; to modify.
    “It gilds all objects, but it alters none.” Pope.
    “My covenant will I not break, nor alter the thing that is gone out of my lips.” — Ps. lxxxix. 34.
  2. 2.
    To agitate; to affect mentally.[Obs.]
  3. 3.
    To geld.[Colloq.]
Syn. Change, Alter.
Change is generic and the stronger term. It may express a loss of identity, or the substitution of one thing in place of another; alter commonly expresses a partial change, or a change in form or details without destroying identity.
02 v. i. To become, in some respects, different; to vary; to change; as, the weather alters almost daily; rocks or minerals alter by exposure.
  1. 1.
    To become, in some respects, different; to vary; to change; as, the weather alters almost daily; rocks or minerals alter by exposure.