To sugarcoat something means to make it seem better than it really is, usually by saying only the good things about it.
When something is sugarcoated, it might not be true or honest. People might do it to be nice or to avoid hurting someone's feelings.
Examples:
She sugarcoated the bad news to make it sound better.
The advertisement sugarcoated the product's problems.
He always sugarcoats his mistakes to avoid getting in trouble.
I don't want you to sugarcoat it, just tell me the truth.
The teacher sugarcoated the test results to make the students feel better.
The politician sugarcoated his promises, but didn't keep them.