The Collaborative International Dictionary of English v.0.48:

Quantify \Quan"ti*fy\, v. t. [L. quantus now much + -fy.]
   1. To modify or qualify with respect to quantity; to
      determine, fix or express the quantity of; to rate.
      [1913 Webster]

   2. (Logic) To make explicit the quantity of; as, to quantify
      a variable.
      [PJC]

WordNet (r) 3.0 (2006):

quantify
    v 1: use as a quantifier
    2: express as a number or measure or quantity; "Can you quantify
       your results?" [syn: quantify, measure]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "quantify":
   apportion, appraise, appreciate, assay, assess, calculate,
   calibrate, caliper, call off, call over, call the roll, census,
   check a parameter, compute, count, decrease, dial, divide,
   enumerate, estimate, evaluate, fathom, fix, foliate, gauge,
   graduate, increase, measure, mensurate, mete, meter, number,
   numerate, pace, page, paginate, parcel, plumb, poll, prize, probe,
   quantize, rate, reduce, run over, size, size up, sound, span, step,
   survey, take a reading, tally, tell, triangulate, valuate, value,
   weigh



The Free On-line Dictionary of Computing (30 December 2018):

Quantify

   A performance analysis tool from Pure Software.