Definitions:

1. A sac-like structure in the inner ear that helps detect vertical movements and contributes to balance by sensing gravity and acceleration. NOUN
   • The sacculus is involved in the perception of the head tilt and linear acceleration.
2. A small sac-like structure, similar to the saccule, often found in anatomy and biology, that refers to the smaller of the two otolith organs located in the inner ear. NOUN
   • The sacculus plays a key role in helping us stay balanced during sudden vertical movements.

Synonyms:

• saccule