1. (of a body of water) being deficient in plant nutrients, such as nitrogen or phosphorus 
2. (of a diet) being deficient in nutrition

Encyclopedia: Oligotrophic

• imperishingness
• imperium
• impermanence
• impermanency
• impermanent
• impermeability
• impermeable
• impermeableness
• impermissibility
• impermissible
• impermissibly
• impersonal
• impersonality
• impersonally
• impersonate
• impersonation
• impersonator
• impertinence
• impertinent
• impertinently
• imperturbability
• imperturbable
• imperturbableness
• imperturbably
• imperviable