Final answer:
The term relating to 'Swagger; show off' is 'swagger,' which describes walking or behaving confidently, sometimes arrogantly, and often includes elements of showing off.
Step-by-step explanation:
The term that matches the definition 'Swagger; show off' is 'swagger'. When someone has swagger, they walk or behave in a very confident and typically arrogant or aggressive way. It often implies a sense of showmanship or the desire to show off one's abilities or qualities.
For instance, a sentence describing the term could be: 'The lead singer walked onto the stage with a swagger, confident in his ability to captivate the audience.' This sentence illustrates the term's connotation of carrying oneself with confidence and a bit of arrogance, which could be perceived as showing off.