1.VerbTo ensure that something specific happens, is done etc., or of something happening. .mw-parser-output .defdate{font-size:smaller}
"I'm going to make sure that I get to the interview on time.; I expected to be able to get to the interview on time, but I left home earlier than usual just to make sure."
2.VerbTo make oneself certain (of something, or that something is the case); to verify, to ascertain.
"When you leave, make sure you have locked the door behind you.; Make sure of your sources before you publish."
3.VerbTo feel certain of something; to be convinced.