From Longman Dictionary of Contemporary Englishlong facelong facea sad or disappointed expression on someone’s face → long
Examples from the Corpus
long face• Never-ending telly, Mum's long face, and a turkey dinner that nobody wanted to eat, not even Henry.• He was in his early thirties with dark skin and a long face from which protruded a sharp, aquiline nose.• A long face, hangdog, sad-sack, and dusty hair, reddish brown.• Do they really physically raise a sardonic eyebrow, and make a long face, or only metaphorically?• His long face, punctuated by a pencil mustache, is a place of jowls, creases and inflammation.• Their faces slipped through her mind, round faces and long faces, thin, fat, smiling, sombre.• His eyes were wide-set, and his long face was fair-skinned: seen from certain angles it had an almost feminine prettiness.• Worst of all, his long face was more contorted than ever in the fury of self-pity. 