indefinable /in-di-fīˈnə-bl/

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

• racecards
• racecourse
• racecourses
• race-cup
• race-cups
• raced
• racegoer
• racegoers
• racegoing
• racegoings
• race hatred
• racehorse
• racehorses
• racemate
• racemates
• racemation
• racemations
• raceme
• racemed
• race meeting
• race meetings
• race memory
• racemes
• racemic
• racemisation