1. a past history of having done bad things or been in trouble; a personal history that includes both successes and failures, or ethical and unethical behavior

1. Larry has quite a checkered past, but things are getting better. He has a new job and is saving for a new apartment.

2. The personnel director of the company refused to consider Mr. Dupont’s application for employment because of his checkered past.

3. The senator has a checkered past.