Source : Webster's Revised Unabridged Dictionary (1913)

Auxesis \Aux*e"sis\, n. [NL., Gr. ? increase, fr. ?, ?, to
   increase.] (Rhet.)
   A figure by which a grave and magnificent word is put for the
   proper word; amplification; hyperbole.

Source : WordNet®

auxesis
     n : growth from increase in cell size without cell division