To acknowledge someone, to speak to someone.
This is a common usage in Kerala.
. A little gupshup
Lata: Look, there's Geeta's new husband.
Meena: Where is Rakesh, then?
Lata: He is with that new girl, no? Sunu.
Meena: Oh? Did they meet? Geeta and Sunu?
Lata: Oh, I saw Geeta and Rakesh talking. But she didn't give Sunu any mind. Rightly, na? Full ignore.