flex flex /ˈflɛks/

noun

1. The act of flexing  ( flex )
   the act of flexing
    He gave his biceps a flex to impress the ladies
   he gave his biceps a flex to impress the ladies
   

verb

1. () Contract  ( flex )
   contract
    Flex a muscle
   flex a muscle
   
2. Cause (a plastic object) to assume a crooked or angular form  ( deform , flex , turn , bend , twist )
   cause (a plastic object) to assume a crooked or angular form
    Bend the rod
   bend the rod
    Twist the dough into a braid
   twist the dough into a braid
    The strong man could turn an iron bar
   the strong man could turn an iron bar
   
3. Bend a joint  ( bend , flex )
   bend a joint
    Flex your wrists
   flex your wrists
    Bend your knees
   bend your knees
   
4. Form a curve  ( flex , bend )
   form a curve
    The stick does not bend
   The stick does not bend
   
5. Exhibit the strength of  ( flex )
   exhibit the strength of
    The victorious army flexes its invincibility
   The victorious army flexes its invincibility