From Longman Dictionary of Contemporary Englishgimlet-eyed/gimlet eyesgimlet-eyed/gimlet eyesNOTICEif someone is gimlet-eyed, or has gimlet eyes, they look at things very hard and notice every detail → gimlet
Examples from the Corpus
gimlet-eyed/gimlet eyes• I-Ie had gimlet eyes and a notably still, restrained manner. 