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

• malignant anemia
• malignant hepatoma
• malignant hypertension
• malignant hyperthermia
• malignant melanoma
• malignant neoplasm
• malignant neoplastic disease
• malignant neuroma
• malignant pustule
• malignant tumor
• malignant tumour
• malignantly
• maligner
• malignity
• malignly
• malignment
• malik
• malinger
• malingerer
• malingering
• malinois
• Malinowski
• malison
• malkin
• mall