'directivity' definitions:

Definition of 'directivity'

(from WordNet)
noun
The property of a microphone or antenna of being more sensitive in one direction than in another; "the antenna received signals with no directivity" [syn: directivity, directionality]
noun
The quality of being directive [syn: directivity, directiveness]

Definition of 'directivity'

From: GCIDE
  • directivity \directivity\ n. the property of a microphone or antenna of being more sensitive to sounds coming from one direction than from another.
  • Syn: directionality. [WordNet 1.5]