1. Not capable of being improved on
   - unexceeded, unsurpassed

See also: best

• Insecta
• insectan
• insecticidal
• insecticidally
• insecticide
• insectifuge
• insectile
• Insectivora
• insectivore
• insectivorous
• insecure
• insecurely
• insecureness
• insecurity
• inseminate
• insemination
• insensate
• insensately
• insensibility
• insensible
• insensibly
• insensitive
• insensitively
• insensitiveness
• insensitivity