flex 1
/fleks/ , v.t.
1. to bend, as a part of the body: He flexed his arms to show off his muscles.
2. to tighten (a muscle) by contraction.
v.i.
3. to bend.
n.
4. the act of flexing.
5. Brit.
a. any flexible, insulated electric cord; an electric cord or extension cord.
b. Slang. an elastic band, as a garter.
6. Math. an inflection point.
[ 1515-25; (adj.) flexus, ptp. of flectere to bend, turn; (n.) flexus act of bending, equiv. to flect ( ere ) + -tus suffix of v. action ]
flex 2
/fleks/ , adj.
Informal. flexible: a flex program of workers' benefits.
[ shortening of FLEXIBLE ]