\But"tress\, n. [OE. butrasse, boterace, fr. F. bouter
to push; cf. OF. bouteret (nom. sing. and acc. pl. bouterez)
buttress. See {Butt} an end, and cf. {Butteris}.]
1. (Arch.) A projecting mass of masonry, used for resisting
   the thrust of an arch, or for ornament and symmetry.
Note: When an external projection is used merely to stiffen a
      wall, it is a pier.
2. Anything which supports or strengthens. ``The ground
   pillar and buttress of the good old cause of
   nonconformity.'' --South.
{Flying buttress}. See {Flying buttress}.

\But"tress\, v. t. [imp. & p. p. {Buttressed} (?); p.
pr. & vb. n. {Buttressing}.]
To support with a buttress; to prop; to brace firmly.
      To set it upright again, and to prop and buttress it up
      for duration.                            --Burke.