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

• willing
• willing and able
• willingly
• willingness
• Willis
• williwaw
• willow
• willow aster
• willow bell
• willow family
• willow oak
• willow tree
• willow-pattern
• willowherb
• willowware
• willowy
• willpower
• willy
• Willy Brandt
• willy-nilly
• willy-willy
• Wilmington
• Wilms' tumor
• Wilms' tumour
• Wilmut