What is the meaning of the word "model"?

Definitions:

a hypothetical description of a complex entity or process noun
- the computer program was based on a model of the circulatory and respiratory systems
a person who poses for a photographer or painter or sculptor noun
- the president didn't have time to be a model so the artist worked from photos
a type of product noun
- The car was an old model.
construct a model of verb
- model an airplane
display clothes as a mannequin verb
- They were asked to model the latest fashion.
form in clay, wax, etc verb
- model a head with clay
someone worthy of imitation noun
- every child needs a role model