flexion /flekˈshən/ noun

1. A bend
2. A fold
3. The action of a flexor muscle
4. Inflexion (grammar)

flexographˈic adjective

flexogˈraphy noun

(Gr graphein to write) (printed matter, esp on plastic, produced by) a method of rotary printing using flexible rubber plates and spirit-based inks

flexˈor noun

A muscle that bends a joint, opp to extensor

flexˈūose or flexˈūous adjective

1. Full of windings and turnings
2. Undulating

flexural /flekˈshər-əl/ adjective

flexˈure noun

1. A bend or turning
2. The curving of a line or surface (mathematics)
3. The bending of loaded beams
4. Obsequious bowing (Shakespeare)

flex'-fuel noun

A fuel consisting of a mixture of petrol and ethanol

adjective

Denoting an engine or vehicle that can run on such fuel or on either of two different kinds of fuel

flexible disk noun (computing)

A floppy disk

flexible drive noun

A means of conveying rotational motion along a flexible cable, or the cable itself

flex one's muscles

To cause the muscles of one's arms, shoulders, etc to contract, in order to display them, test them as a preliminary to a trial of strength, etc (often figurative)