Meaning 1 ►▼
The batter has only one more strike before he is out
He hit a home run into left field with two strikes against him.
Meaning 2 ►▼
to have one more chance
He had two strikes against him when he interviewed for the job. He had been in prison and had never had a job.
The word "strike" probably is derived from the English game cricket. A batter in cricket is a "striker."