indefinable /in-di-fīˈnə-bl/

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

• hypostrophe
• hypostrophes
• hypostyle
• hypostyles
• hyposulphate
• hyposulphates
• hyposulphite
• hyposulphites
• hyposulphuric
• hyposulphurous acid
• hypotactic
• hypotaxes
• hypotaxis
• hypotension
• hypotensions
• hypotensive
• hypotensives
• hypotenuse
• hypotenuses
• hypothalami
• hypothalamic
• hypothalamus
• hypothalamuses
• hypothec
• hypothecary