1. A challenge to defend what someone has said
   - demand for explanation

Type of: challenge

• sex segregation
• sex shop
• sex symbol
• sex toy
• sex up
• sex-change operation
• sex-limited
• sex-linked
• sex-linked disorder
• sex-starved
• sexadecimal notation
• sexadecimal number system
• sexagenarian
• Sexagesima
• sexagesimal
• sexcapade
• sexed
• sexily
• sexiness
• sexism
• sexist
• sexless
• sexlessness
• sexologist
• sexology