1. Very clearly delineated
   "razor-sharp definition" 
2. As sharp as a razor

See also: distinct, sharp

• office-bearer
• officeholder
• officer
• officer's mess
• official
• official document
• official emissary
• official immunity
• officialdom
• officialese
• officialise
• officialism
• officialize
• officially
• officiant
• officiate
• officiating
• officiation
• officiator
• officinal
• officious
• officiously
• officiousness
• offing
• offish