From BiblePortal Wikipedia

King James Dictionary [1]

Al'Ter, L. alter, another. See Alien.

1. To make some change in to make different in some particular to vary in some degree, without an entire change.

My covenant will I not break, nor alter the thing that has gone out of my lips.  Psalms 89 .

2. To change entirely or materially as, to alter an opinion. In general, to alter is to change partially to change is more generally to substitute one thing for another, or to make a material difference in a thing.

Al'Ter, To become, in some respects, different to vary as, the weather alters almost daily.

The law which altereth not.  Daniel 4 .

Webster's Dictionary [2]

(1): (v. t.) To agitate; to affect mentally.

(2): (v. i.) To become, in some respects, different; to vary; to change; as, the weather alters almost daily; rocks or minerals alter by exposure.

(3): (v. t.) To make otherwise; to change in some respect, either partially or wholly; to vary; to modify.

(4): (v. t.) To geld.