win‧now /ˈwɪnəʊ $ -noʊ/ (also winnow down) verb
[Language: Old English; Origin: windwian]
[transitive] to make a list, group, or quantity smaller by getting rid of the things that you do not need or want Synonym : whittle down:
We need to winnow the list of candidates to three.
winnow somebody/something ↔ out phrasal verb
to get rid of the things or people that you do not need or want from a group

[TahlilGaran] Dictionary of Contemporary English ▲