The Collaborative International Dictionary of English v.0.48:

Portraiture \Por"trai*ture\, v. t.
   To represent by a portrait, or as by a portrait; to portray.
   [R.] --Shaftesbury.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Portraiture \Por"trai*ture\ (?; 135), n. [F. portraiture.]
   1. A portrait; a likeness; a painted resemblance; hence, that
      which is copied from some example or model.
      [1913 Webster]

            For, by the image of my cause, I see
            The portraiture of his.               --Shak.
      [1913 Webster]

            Divinity maketh the love of ourselves the pattern;
            the love of our neighbors but the portraiture.
                                                  --Bacon.
      [1913 Webster]

   2. Pictures, collectively; painting. [Obs.] --Chaucer.
      [1913 Webster]

   3. The art or practice of making portraits. --Walpole.
      [1913 Webster]

WordNet (r) 3.0 (2006):

portraiture
    n 1: a word picture of a person's appearance and character [syn:
         portrayal, portraiture, portrait]
    2: the activity of making portraits

Moby Thesaurus II by Grady Ward, 1.0:

95 Moby Thesaurus words for "portraiture":
   acrylic painting, alphabet, art, blueprint, cameo, catalog,
   cataloging, character, character sketch, charactering,
   characterization, chart, choreography, coloring,
   conventional representation, dance notation, delineation,
   demonstration, depiction, depictment, description, details,
   diagram, drama, drawing, encaustic cerography, encaustic painting,
   evocation, exemplification, figuration, finger painting,
   flower painting, fresco painting, genre painting, gouache,
   graphic account, grisaille, head, hieroglyphic, iconography,
   ideogram, illumination, illustration, image, imagery, imaging,
   impasto, impression, itemization, letter, limning, logogram,
   logograph, map, miniature, monochrome, mural painting,
   musical notation, notation, oil painting, painting,
   particularization, photograph, pictogram, picture, picturization,
   plan, portrait, portrayal, poster painting, prefigurement,
   presentment, printing, profile, projection, realization, rendering,
   rendition, representation, schema, score, script, silhouette,
   sketch, specification, syllabary, symbol, tablature, the brush,
   vignette, vivid description, wash, wash drawing, word painting,
   writing