1. brace  (noun) 

a structural member used to stiffen a framework

  Also known as: bracing

  More Specific:

crosspiece - a transverse brace
gusset / gusset plate - a metal plate used to strengthen a joist
guy / guy cable / guy rope - a rope or cable that is used to brace something (especially a tent)
stay - (nautical) brace consisting of a heavy rope or wire cable used as a support for a mast or spar
stringer - brace consisting of a longitudinal member to strengthen a fuselage or hull
strut - brace consisting of a bar or rod used to resist longitudinal compression
tie / railroad tie / crosstie / sleeper - one of the cross braces that support the rails on a railway track

  Part Meronym:

    framework     frame     framing

  More Generic:

    structural member     strengthener     reinforcement

2. brace  (noun) 

the stock of a tool used for turning a drilling bit

  Also known as: bitstock

  Part Meronym:

    brace and bit

  More Generic:

    stock

3. brace  (noun) 

an appliance that corrects dental irregularities

  Also known as: braces

  More Generic:

    dental appliance

4. brace  (noun) 

a support that steadies or strengthens something else; "he wore a brace on his knee"

  More Specific:

ankle brace - a brace worn to strengthen the ankle
back brace - a brace worn to support the back
knee brace - a brace worn to strengthen the knee
neck brace - a brace worn to steady the neck
skeg - a brace that extends from the rear of the keel to support the rudderpost

  More Generic:

    support     strengthener     reinforcement

5. brace  (noun) 

elastic straps that hold trousers up (usually used in the plural)

  Also known as: suspender / gallus

  More Generic:

    clothing     article of clothing     vesture     wear

6. brace  (noun) 

a rope on a square-rigged ship that is used to swing a yard about and secure it

  More Specific:

royal brace - a brace to secure the royal mast

  More Generic:

    rope

7. brace  (noun) 

either of two punctuation marks ({ or }) used to enclose textual material

  More Generic:

    punctuation     punctuation mark

8. brace  (noun) 

a set of two similar things considered as a unit

  Also known as: pair

  More Specific:

Tweedledum and Tweedledee / Tweedledee and Tweedledum - any two people who are hard to tell apart

  More Generic:

    set

9. brace  (noun) 

two items of the same kind

  Also known as: couple / pair / twosome / twain / span / yoke / couplet / distich / duo / duet / dyad / duad

  More Specific:

doubleton - (bridge) a pair of playing cards that are the only cards in their suit in the hand dealt to a player

  More Generic:

    two     2     II     deuce

10. brace  (verb) 

cause to be alert and energetic; "Coffee and tea stimulate me"; "This herbal infusion doesn''t stimulate"

  Also known as: stimulate / arouse / energize / energise / perk up

  More Specific:

cathect - inject with libidinal energy
animate / recreate / reanimate / revive / renovate / repair / quicken / vivify / revivify - give new life or energy to
invigorate / reinvigorate - impart vigor, strength, or vitality to
enliven / liven / liven up / invigorate / animate - make lively

  More Generic:

    affect

  Opposite of:

    de-energize     de-energise     de-energize     de-energise     sedate     calm     tranquilize     tranquillize     tranquillise

11. brace  (verb) 

support by bracing

  More Specific:

tread - brace (an archer''s bow) by pressing the foot against the center

  More Generic:

    hold     support     sustain     hold up

12. brace  (verb) 

support or hold steady and make steadfast, with or as if with a brace; "brace your elbows while working on the potter''s wheel"

  Also known as: steady / stabilize / stabilise

  More Specific:

ballast - make steady with a ballast
guy - steady or support with with a guy wire or cable

  More Generic:

    strengthen     beef up     fortify

13. brace  (verb) 

prepare (oneself) for something unpleasant or difficult

  Also known as: poise

  More Specific:

steel / nerve - get ready for something difficult or unpleasant

  More Generic:

    fix     prepare     set up     ready     gear up     set