Synonyms for Filling:

n.

flock, pad, backing, kapok. bun, biscuit, Christmas Cake, cake mix, cone, brownie, cake, cheesecake, chocolate chip cookie, baking sheet. calorific, chewy, chilled, crisp, buttery, caramelized, cool, crispy. contents (noun)
guts.
dentistry (noun)
braces, bridge, cap, cavity, amalgam, dentistry, caries, crown.
filling (noun)
fill, pick, layer, pad, weft, stuffing, bushing, dressing, center, insides, mixture, padding, filler, woof, innards, wadding.
filling/filler (noun)
contents.
lining (noun)
bushing.
ornament (noun)
badge, foofaraw, Emblazonment, trimming, adornment, flourish, gaudiness, button, embroidery, ornament, trim, gingerbread, garnish, finery, frill, tinsel, gewgaw, enrichment, decoration, emblem.
stuffing (noun)
contents, lining, filler, innards, sauce, mixture, bushing, center, cement, insides, guts, layer, custard, wadding, dressing, padding.
substance (noun)
fill.

v.

completing (verb)
Consummating, integrating, executing, finishing, arriving, unifying, closing, Fulfilling, Accomplishing, Achieving, finalizing, Terminating, Graduating, Culminating, concluding, completing, ending.
infusing (verb)
Infiltrating, pervading, Imbuing, Infusing, instilling, seething, Impregnating, soaking, permeating, Suffusing, penetrating.
satisfying (verb)
quenching, Glutting, Saturating, Allaying, gratifying, stuffing, Sating, Satiating, appeasing, Slaking, satisfying, Engorging, Gorging.

Other synonyms:

dressing, kapok, contents. backing, lining. flock. cushion
pad.
filling
padding.
Other relevant words:
contents, fill, dressing, weft, cap, pad, pick, insides, innards, amalgam, woof, layer, crown, lining, padding, filler, wadding, bushing.

Usage examples for filling

  1. " Why, we can't let Hume-" He broke off suddenly, his eyes filling with light. – The Short Cut by Jackson Gregory
  2. Having on one occasion, while filling the office of Lord- Lieutenant, had the honour to receive the Prince of Wales at Dublin, he could state from his own knowledge that His Royal Highness took the deepest interest in all that concerned the welfare of Ireland, and showed the greatest anxiety to make himself acquainted with her affairs. – Speeches and Addresses of H. R. H. the Prince of Wales: 1863-1888 by Edward VII