Alternative form of he who hesitates is lost

(Australia, New Zealand, US, idiomatic) An expression used to mean "We have been caught out and have no defense", or if spoken to a person who has just been found out as the perpetrator of an offense, where it means "You've been discovered".

(idiomatic) Alternative form of the jig is up [for one].

To make or take a bet. / (idiomatic) To take an obvious stake in the truth of a claim that one is making.

That is the way things happen / Certain things cannot be changed, helped or improved; struggle and objection are pointless.

It is allowable to retaliate against an enemy's dirty tricks by using the same ones against them. / Taking turns is morally right.

Initialism of International Sign. / (computing) Initialism of information system(s). / (politics) Initialism of international studies. / (finance) Initialism of implementation shortfall.

(biblical) Abbreviation of Isaiah.

Initialism of Islamic State. / (languages) Initialism of Interior Salish.

(idiomatic) One is offended or angry.