The Collaborative International Dictionary of English v.0.48:

Savvy \Sav"vy\, Savvey \Sav"vey\, v. t. & i. [Written also
   savey.] [Sp. saber to know, sabe usted do you know?]
   To understand; to comprehend; know. [Slang, U. S.]
   [Webster 1913 Suppl.] Savvy

The Collaborative International Dictionary of English v.0.48:

Savvy \Sav"vy\, Savvey \Sav"vey\, n.
   Comprehension; knowledge of affairs; mental grasp; also,
   practical know-how; common sense. [Slang, U. S.] also adj.
   knowledgeable; well-informed; clever; canny; wise.
   [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

savvy
    n 1: the cognitive condition of someone who understands; "he has
         virtually no understanding of social cause and effect"
         [syn: understanding, apprehension, discernment,
         savvy]
    v 1: get the meaning of something; "Do you comprehend the
         meaning of this letter?" [syn: grok, get the picture,
         comprehend, savvy, dig, grasp, compass,
         apprehend]

Moby Thesaurus II by Grady Ward, 1.0:

166 Moby Thesaurus words for "savvy":
   ability, absorb, acuity, acuteness, address, adeptness, adroitness,
   airmanship, appreciate, apprehend, apprehension, aptitude, aptness,
   artfulness, artisanship, artistry, assimilate, astute,
   be acquainted with, be apprised of, be aware of, be cognizant of,
   be conscious of, be conversant with, be informed, be with one,
   braininess, bravura, brightness, brilliance, cagey, capability,
   capacity, catch, catch on, clairvoyance, clear thinking,
   cleverness, cognize, command, competence, comprehend,
   comprehension, conceive, conception, conceptualization,
   conceptualize, control, coordination, craft, craftsmanship,
   cunning, deftness, dexterity, dexterousness, dextrousness, dig,
   digest, diplomacy, discern, efficiency, esprit, expertise,
   facility, fathom, finesse, flair, follow, foreknowledge, genius,
   get, get hold of, get the drift, get the idea, get the picture,
   giftedness, gifts, grace, grasp, grip, handiness, have,
   have information about, have it taped, have knowledge of, heady,
   horsemanship, ideation, ingeniousness, ingenuity, intellection,
   intelligence, keen-wittedness, keenness, ken, know, know-how,
   learn, make out, marksmanship, master, mastership, mastery,
   mental alertness, mental grasp, mercurial mind, native cleverness,
   nimble mind, nimble-wittedness, nimbleness, nous, perceive,
   perspicacious, possess, practical ability, precognition, prehend,
   prehension, proficiency, prowess, quick parts, quick thinking,
   quick wit, quick-wittedness, quickness, read, readiness, ready wit,
   realize, recognize, resource, resourcefulness, sagacious,
   savoir-faire, seamanship, see, seize, seize the meaning, sense,
   sharp-wittedness, sharpness, skill, skillfulness, smartness,
   smarts, sprightly wit, style, tact, tactfulness, take, take in,
   talent, technical brilliance, technical mastery, technical skill,
   technique, timing, understand, understanding, virtuosity, wisdom,
   wit, wizardry, workmanship, wot, wot of