Webster's Revised Unabridged Dictionary · 1913

Augment

Augment ({not transcribed}) , transitive verb

[Latin augmentare, from augmentum an increase, from augere to increase; perh. akin to Greek {not transcribed}, {not transcribed}, English wax, v., and eke, v.: compare French augmenter.]

1.
To enlarge or increase in size, amount, or degree; to swell; to make bigger; as, to augment an army by reeforcements; rain augments a stream; impatience augments an evil.
But their spite still serves His glory to augment. — Milton
2.
(Grammar) To add an augment to.

Augment , intransitive verb

To increase; to grow larger, stronger, or more intense; as, a stream augments by rain.

Augment ({not transcribed}) , noun

[Latin augmentum: compare French augment.]

1.
Enlargement by addition; increase.
2.
(Grammar) A vowel prefixed, or a lengthening of the initial vowel, to mark past time, as in Greek and Sanskrit verbs.

In Greek, the syllabic augment is a prefixed {not transcribed}, forming an intial syllable; the temporal augment is an increase of the quantity (time) of an initial vowel, as by changing {not transcribed} to {not transcribed}.