1. to refuse to allow or permit; to reject as invalid or unacceptable
Usage: third person singular present tense of ‘disallow’

Examples

• The referee disallows the goal due to an offside violation.
• The company policy disallows personal use of office equipment.
• The judge disallows the evidence because it was obtained illegally.
• The system disallows passwords shorter than eight characters.
• The school disallows cell phone use during class hours.
• The insurance company disallows claims filed after the deadline.