I encountered this word in an astronomy article in DISCOVER magazine. I checked, and found
it had been used in AWADtalk, twice erroneously, and never defined.
The errors consisted of not noticing the difference between singular and plural.

cognoscente (too bad the pron;unciation marks are garbage. The "g" is not hard = conyoshentay?
n.,
pl. ti orig. prp. of conoscere, to know < L cognoscere: see COGNITION6 a person with special knowledge in some field, esp. in the fine arts; expert