From Longman Dictionary of Contemporary Englishtight-lippedtight-lipped /ˌtaɪt ˈlɪpt◂/ adjective 1 DISCUSS#unwilling to talk about something Diplomats are remaining tight-lipped about the negotiations.2 ANGRYwith your lips tightly pressed together because you are angry
Examples from the Corpus
tight-lipped• He stared at her, tight-lipped.• Developers are staying tight-lipped about details of the housing scheme until a formal announcement is made.• Authorities have been extremely tight-lipped about the investigation.• The Levys stayed tight-lipped after the first day's hearing.• Most of her friends worked at the agency or in defense jobs and shared the same tight-lipped demeanor.• She took the report, went out into the department and threw herself into her work with tight-lipped determination.• After her return, she had spent the first week weeping, conscious of her father's tight-lipped disappointment and indignant fury.• Step out of line, demand better attention, and you meet tight-lipped disapproval.• According to Mossop, Heather had been tight-lipped during the drive back to Weymouth.• Of course we shall sometimes feel lonely but we were never meant, grim-faced and tight-lipped, to slog on alone. 