Cases of word usage

1) a structure built out into the sea to make the water in a harbour calm (breakwater)

2) a harbour for pleasure boats (small yachts etc) (marina)

3) first and experimental; a person trained to operate the controls of an aircraft; a person able to direct ships in a port, harbour etc (pilot)

4) a town with a harbour used by sea-going ships (seaport)

5) a payment required for the use of a road, bridge, harbour etc; the costs suffered as a result of a war, disease, famine etc; (to cause a bell) to ring with slow, regular sounds (toll)