1. Not knowledgeable about something specified
   "a person unacquainted with our customs"
   - innocent 
2. Having little or no knowledge of
   "unacquainted with city ways"
   - unacquainted with, unfamiliar with

See also: unfamiliar, uninformed

• close shave
• close support
• close supporting fire
• close to
• close to the wind
• close together
• close-cropped
• close-fitting
• close-grained
• close-hauled
• close-knit
• close-minded
• close-order drill
• close-packed
• close-quarter fighting
• closed
• closed book
• closed chain
• closed circuit
• closed corporation
• closed couplet
• closed curve
• closed fracture
• closed gentian
• closed in