1. openly resists or refuses to obey someone or something
Usage: third person singular present tense of ‘defy’
2. appears to make something impossible or very difficult
Usage: third person singular present tense of ‘defy’

Examples

• She defies her parents’ rules about curfew.
• The young rebel defies authority at every turn.
• This problem defies easy solution.
• The ancient building defies the passage of time.
• His success defies all expectations.
• The athlete defies gravity with her incredible jumps.
• The evidence defies logical explanation.