Cases of word usage

1) to encourage a person to be cheerful, finish a task etc by making frequent requests etc (chivvy)

2) a finish of a race that is so close that a photograph is needed to decide the winner (photofinish)

3) any of several subdivisions of mankind sharing certain physical characteristics, especially colour of skin, colour and type of hair, shape of eyes and nose; a contest or competition in speed, e.g. to see who can finish a piece of work or get to a certain place first (race)