Source : Webster's Revised Unabridged Dictionary (1913)

Augmentative \Aug*ment"a*tive\, a. [Cf. F. augmentatif.]
   Having the quality or power of augmenting; expressing
   augmentation. -- {Aug*ment"a*tive*ly}, adv.

Augmentative \Aug*ment"a*tive\, n. (Gram.)
   A word which expresses with augmented force the idea or the
   properties of the term from which it is derived; as, dullard,
   one very dull. Opposed to {diminutive}. --Gibbs.

Source : WordNet®

augmentative
     adj 1: increasing or having the power to increase especially in
            size or amount or degree; "`up' is an augmentative
            word in `hurry up'"
     2: intensifying by augmentation and enhancement [syn: {enhancive}]