To fail or be unsuccessful in an attempt. He struck out in his attempt to secure the job.
To remove or delete something, especially from a document. The editor struck out the unnecessary paragraphs from the article.
To set out on a new course or path. After years in the corporate world, she decided to strike out on her own and start a business.
In baseball, to be declared out after three strikes. The batter struck out swinging at the last pitch.