1. Of biological parents not married to each other
   - illegitimately 
2. Of unwed parents
   "he was born out of wedlock"
   - outside marriage

Encyclopedia: Out of wedlock

• defenseless
• defenselessly
• defenselessness
• defenseman
• defensibility
• defensible
• defensive
• defensive attitude
• defensive measure
• defensive structure
• defensively
• defensiveness
• defer
• deference
• deferent
• deferential
• deferentially
• deferment
• deferral
• deferred payment
• defervesce
• defervescence
• defervescent
• defiance
• defiant