buccaneer:
(plural: ‘buccaneer the letter ‘u’ in this word rhymes with the letter ‘u’ in ‘but’)

a buccaneer of the 17th century
a thief, a privateer, who looted Spanish ships in the 17th century;
a person who lived/lives a careless life, robbing people, usually the people on the coastal villages and towns;
a sea robber; a pirate;
(in the present day usage) a fearless businessman (speculator) or adventurer,
e.g.
The government of Spain had a very difficult time controlling the buccaneer who, with the support of the British, raided their ships and stole valuables worth millions.
Jason lived a life of a buccaneer and died like a buccaneer.
Some people concerned about the health of the general public accuse the tobacco industry giants of being buccaneer businessmen.
For an informative article explaining the difference in meanings of pirate, buccaneer and privateer, please click here. To see how this word is used in everyday English, please click here.
Note: ‘Buccaneer’, in the present-day usage, is found mostly as the name of some sports club, a seaside resort, a kind of beer, or even an aircraft.
