1. Not easy to understand or use
   "user-unfriendly" 
2. Not disposed to friendship or friendliness
   "an unfriendly coldness of manner"; "an unfriendly action to take" 
3. Not friendly
   "an unfriendly act of aggression"
   - inimical 
4. Very unfavourable to life or growth
   "the unfriendly environment at high altitudes"
   - hostile, uncongenial

See also: beetle-browed, chilly, cool, friendliness, hostile, incompatible, inhospitable, scowling, uncongenial, uncordial, unfriendliness, unneighborly [US], unneighbourly [Brit, Cdn], unsociable

Antonym: friendly

Encyclopedia: Unfriendly

• oxyacetylene
• oxyacetylene torch
• oxyacid
• Oxybelis
• oxybenzene
• oxybutyric acid
• oxycephaly
• oxycodone
• Oxydendrum
• Oxydendrum arboreum
• oxygen
• oxygen acid
• oxygen debt
• oxygen deficit
• oxygen mask
• oxygen tent
• oxygenase
• oxygenate
• oxygenation
• oxygenic
• oxygenise
• oxygenize
• oxyhaemoglobin
• oxyhemoglobin
• Oxylebius