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

• receptively
• receptiveness
• receptivity
• receptor
• recess
• recessed
• recession
• recessional
• recessional march
• recessionary
• recessive
• recessive allele
• recessive gene
• recharge
• rechargeable
• recharter
• recheck
• recherché
• rechewed food
• rechristen
• recidivate
• recidivism
• recidivist
• Recife
• recipe