1. tight-lipped - Adjective
2. tight-lipped - Phrase
(literally) Having the lips pressed tightly together, hence, not speaking.
(idiomatic) Unwilling to divulge information.
Source: en.wiktionary.orgThe party delegate was one of those gloomy, tight-lipped persons who seem to have been made for wearing a red scarf round the neck and a tommy-gun slung from one shoulder. Giovannino Guareschi
I've always enjoyed that kind of thing - thinking about the production of narrative and why it is that when we read a novel, we don't notice the fact that someone who might be very close-mouthed or tight-lipped is perfectly willing to tell us a story in 600 or 700 pages. Matthew Tobin Anderson
There's so many tight-lipped ideas and laws around, and people put themselves in uniforms so tightly, that it's almost impossible to break out of that. Subconsciously, what these people are doing, they're killin' off all these little flashes they have, cutting off the idea of wanting to understand. Jimi Hendrix
Democrats are also eyeing Sen. Lamar Alexander, R-Tenn, who the Hill reported has been tight-lipped on where he stands on the matter. Source: Internet
And Spike's family - Colonel Falconer, his fragile wife Sylvia, and their natural-born son Simon - are keeping tight-lipped, closing ranks. Source: Internet
But she remained tight-lipped over how much she has earned from impersonating Meghan and did not say whether the move to Los Angeles has changed her prospects. Source: Internet