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

See also: distinct, sharp

• up to his neck
• up to my neck
• up to now
• up to our necks
• up to par
• up to scratch
• up to snuff
• up to their necks
• up to your neck
• up-and-coming
• up-bow
• up-to-date
• up-to-dateness
• originate in
• origination
• origination fee
• originative
• originator
• orinasal
• orinasal phone
• Orinase
• Orinoco
• Orinoco River
• oriole
• Oriolidae