A chance for advancement, progress or profit. / A favorable circumstance or occasion. / (nonstandard, Euro-English) opportuneness

plural of opportunity

Suitable for some particular purpose. / At a convenient or advantageous time.

In a manner suitable for some particular purpose. / In a manner convenient or advantageous at some particular time.

plural of opportunism

The practice of taking advantage of any situations or people to achieve an end, often with no regard for principles or consequences.

the state or condition of being opportune

opportunistic

(economics) The cost of an opportunity forgone (and the loss of the benefits that could be received from that opportunity); the most valuable forgone alternative.

(informal, idiomatic) The United States.