If someone looks gaunt, they look very thin, usually because they have been very ill or worried. Looking gaunt and tired, he denied there was anything to worry about. = drawn
very thin especially from disease or hunger or cold; "emaciated bony hands"; "a nightmare population of gaunt men and skeletal boys"; "eyes were haggard and cavernous"; "small pinched faces"; "kept life in his wasted frame only by grim concentration"