indefinable /in-di-fīˈnə-bl/

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

• thick-skulls
• thick-sown
• thick'un
• thick'uns
• thick-witted
• thick-wittedly
• thick-wittedness
• thicky
• thief
• thief-catcher
• thief-catchers
• thieflike
• thief-taker
• thieve
• thieved
• thieveries
• thievery
• thieves
• thieves' kitchen
• thieves' Latin
• thieving
• thievings
• thievish
• thievishly
• thievishness