Opportunistic (adjective)

1. Acting or done with a view to taking immediate advantage of a situation, often without regard to planning or principle.
2. Acting in a way that is determined by the circumstances rather than by a particular principle or ideology.

Origin:

Early 20th century: from french opportuniste (see opportunist) + -ic.

Examples:

1. The company was criticized for its opportunistic business practices.
2. The politician's opportunistic stance on the issue earned him the support of many voters.
3. The opportunistic investor made a fortune by buying low and selling high.
4. The opportunistic behavior of the company led to its downfall.
5. He was an opportunistic individual who would seize any opportunity to gain an advantage.