Definitions of function:

• noun:   the actions and activities assigned to or required or expected of a person or group

  Example: "The function of a teacher"

• noun:   what something is used for

  Example: "The function of an auger is to bore holes"

• noun:   a formal or official social gathering or ceremony

  Example: "It was a black-tie function"

• noun:   a relation such that one thing is dependent on another

  Example: "Height is a function of age"

• noun:   a mathematical relation such that each element of one set is associated with at least one element of another set
• noun:   a vaguely specified social event

  Example: "A seemingly endless round of social functions"

• noun:   a set sequence of steps, part of larger computer program
• verb:   perform as expected when applied
• verb:   serve a purpose, role, or function

  Example: "The table functions as a desk"

• verb:   perform duties attached to a particular office or place or function