indefinable /in-di-fīˈnə-bl/

1. That cannot be defined
2. Hard to identify or describe

• umbrae
• umbrage
• umbraged
• umbrageous
• umbrageously
• umbrageousness
• umbrageousnesses
• umbrages
• umbraging
• umbral
• umbras
• umbrated
• umbratic
• umbratical
• umbratile
• umbratilous
• umbre
• umbrel
• umbrella
• umbrella-ant
• umbrella-ants
• umbrella bird
• umbrella birds
• umbrella'd
• umbrellaed