1. The state or quality of being mysterious 
2. Something mysterious; a mystery

Derived forms: mysteriousnesses

• acoustic phenomenon
• acoustic power
• acoustic projection
• acoustic radiation pressure
• acoustic reactance
• acoustic resistance
• acoustic spectrum
• acoustic storage
• acoustic wave
• acoustical
• acoustically
• acoustician
• acousticophobia
• acoustics
• acquaint
• acquaintance
• acquaintanceship
• acquainted
• acquiesce
• acquiescence
• acquiescent
• acquiescently
• acquirable
• acquire
• acquired