Merriam-Webster Collegiate Dictionary - augment

 I. verb  Etymology: Middle English, from Anglo-French ~er, from Late Latin ~are, from Latin ~um increase, from augere to increase — more at eke  Date: 14th century  transitive verb  1. to make greater, more numerous, larger, or more intense the impact of the report was ~ed by its timing  2. to add an ~ to  3. supplement ~ed her scholarship by working nights  intransitive verb to become ~ed  Synonyms: see increase  • ~er or ~or noun  II. noun  Date: circa 1771 a vowel prefixed or a lengthening of the initial vowel to mark past time especially in Greek and Sanskrit verbs