n. (also cognisance) 1 knowledge or awareness; perception, notice. 2 the sphere of one's observation or concern. 3 Law the right of a court to deal with a matter. 4 Heraldry a distinctive device or mark. have cognizance of know, esp. officially. take cognizance of attend to; take account of.
[ ME f. OF conoisance ult. f. L cognoscent- f. cognitio: see COGNITION ]