WordNet (r) 3.0 (2006):

get the picture
    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:

33 Moby Thesaurus words for "get the picture":
   absorb, appreciate, apprehend, assimilate, be with one, catch,
   catch on, comprehend, conceive, dig, digest, fathom, follow, get,
   get hold of, get the drift, get the idea, grasp, have,
   have it taped, ken, know, learn, master, read, realize, savvy,
   seize, seize the meaning, sense, take, take in, understand