The difference between Curb and Flex

Curb as a noun (North America):

A concrete margin along the edge of a road; a kerb (UK)

Curb as a noun:

A raised margin along the edge of something, such as a well or the eye of a dome, as a strengthening.

Curb as a noun:

Something that checks or restrains; a restraint.

Curb as a noun:

A riding or driving bit for a horse that has rein action which amplifies the pressure in the mouth by leverage advantage placing pressure on the poll via the crown piece of the bridle and chin groove via a curb chain.

Curb as a noun (North America):

A sidewalk, covered or partially enclosed, bordering the airport terminal road system with an adjacent paved areas to permit vehicles to off-load or load passengers.

Curb as a noun:

A swelling on the back part of the hind leg of a horse, just behind the lowest part of the hock joint, generally causing lameness.

Curb as a verb (transitive):

To check, restrain or control.

Curb as a verb (transitive):

To rein in.

Curb as a verb (transitive):

To furnish with a curb, as a well; to restrain by a curb, as a bank of earth.

Curb as a verb (transitive):

To force to "bite the curb" (hit the pavement curb); see curb stomp.

Curb as a verb (transitive):

To damage vehicle wheels or tires by running into or over a pavement curb.

Curb as a verb (transitive):

To bend or curve.

Curb as a verb (intransitive):

To crouch; to cringe.

Flex as a noun (uncountable):

Flexibility, pliancy.

Flex as a noun (countable):

The act of flexing.

Flex as a noun (uncountable, chiefly, British):

Any flexible insulated electrical wiring.

Flex as a noun (countable, geometry):

A point of inflection.

Flex as a verb:

To bend something.

Flex as a verb:

To repeatedly bend one of one's joints.

Flex as a verb:

To move part of the body using one's muscles.

Flex as a verb:

To tighten the muscles for display of size or strength.

Flex as a verb (slang, by extension):

To flaunt one's superiority.