The Collaborative International Dictionary of English v.0.48:

Motif \Mo"tif\, n. [F.]
   Motive. [archaic]
   [1913 Webster]

   2. In literature and the fine arts, a salient feature or
      element of a composition or work; esp., the theme, or
      central or dominant feature; specif. (Music), a motive[3].
      See also leitmotif.
      [Webster 1913 Suppl. +PJC]

            This motif, of old things lost, is a favorite one
            for the serious ballade.              --R. M. Alden.
      [Webster 1913 Suppl.]

            The design . . . is . . . based on the peacock -- a
            motif favored by decorative artists of all ages.
                                                  --R. D. Benn.
      [Webster 1913 Suppl.]

   3. (Dressmaking) A decorative appliqu['e] design or figure,
      as of lace or velvet, used in trimming; also, a repeated
      design.
      [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

motif
    n 1: a design or figure that consists of recurring shapes or
         colors, as in architecture or decoration [syn: motif,
         motive]
    2: a theme that is repeated or elaborated in a piece of music
       [syn: motif, motive]
    3: a unifying idea that is a recurrent element in literary or
       artistic work; "it was the usual `boy gets girl' theme" [syn:
       theme, motif]

Moby Thesaurus II by Grady Ward, 1.0:

121 Moby Thesaurus words for "motif":
   action, anagnorisis, angle, architectonics, architecture, argument,
   atmosphere, background, background detail, basis, beading, binding,
   bordering, bordure, burden, case, catastrophe, chapter,
   characterization, color, complication, concept, concern,
   continuity, contrivance, convention, decoration,
   decorative composition, decorative style, denouement, design,
   detail, development, device, edging, element, episode, essence,
   fable, falling action, figure, fimbria, fimbriation, flounce,
   focus of attention, focus of interest, foil, foreground detail,
   form, frill, frilling, fringe, furbelow, galloon, gimmick, gist,
   head, heading, hem, idea, incident, issue, leitmotif, leitmotiv,
   line, list, living issue, local color, main point, matter,
   matter in hand, meat, mood, motive, movement, mythos,
   national style, ornament, ornamental motif, pattern, period style,
   peripeteia, phrase, plan, plot, point, point at issue,
   point in question, problem, question, recognition, refrain,
   repeated figure, rising action, rubric, ruffle, scheme,
   secondary plot, selvage, setting, skirting, slant, story,
   structure, style, subject, subject matter, subject of thought,
   subplot, substance, switch, text, thematic development, theme,
   tone, topic, touch, trimming, twist, valance, welt



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

Motif

   The standard graphical user interface and window manager
   from OSF, running on the X Window System.