op‧por‧tun‧ist /ˌɒpəˈtjuːnəst, ˌɒpəˈtjuːnɪst $ ˌɑːpərˈtuː-/ noun [countable]

1. someone who uses every opportunity to gain power, money, or unfair advantages – used to show disapproval:
Voters dislike opportunists – politicians who change their policies according to opinion polls.

2. someone who commits a crime because they have a chance to, and not because they planned to:
Most burglars are opportunists.
an opportunist crime
—opportunist adjective:
the opportunist policies of wartime leaders
—opportunistic /ˌɒpətjuːˈnɪstɪk◂ $ ˌɑːpərtuː-/ adjective:
opportunistic thefts from cars

[TahlilGaran] Dictionary of Contemporary English ▲