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

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

plural of opportunity

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

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

plural of opportunism

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.

(theology) The idea, particularly in Christianity, that an opportunity to follow the deity, e.g. Jesus, will be an option at the time of death.