know ‧ ing /ˈnəʊɪŋ $ ˈnoʊ-/ BrE AmE adjective [only before noun]
[ Word Family: adjective : ↑ knowing , ↑ knowledgeable , ↑ known ≠ ↑ unknown ; noun : ↑ knowledge , the unknown; adverb : ↑ knowingly ≠ ↑ unknowingly , ↑ knowledgeably ; verb : ↑ know ]
showing that you know all about something, even if it has not been discussed directly:
He gave us a knowing look.
She exchanged a knowing smile with her mother.