opportunistic

/หŒษ‘pษ™ษนหŒtuหหˆnษชstษชk/
adjective
  1. 1

    Taking advantage of situations that arise.

    โ€œThe danger now isn't so much from the AIDS virus itself as from opportunistic infections.โ€

  2. 2

    Taking advantage of situations to advance one's own interests without regard for moral principles.

    โ€œYou can't trust somebody that opportunistic: he'll stab you in the back the first chance he gets.โ€

Source: https://en.wiktionary.org/wiki/opportunistic