1 عمومی:: قیافه بی تفاوت، چهره رسمی و بی نشاط
شبکه مترجمین ایران
1 general:: Phrase(s): *a straight face Fig. a face free from smiles or laughter. (*Typically: have ~; keep ~.) • It’s hard to keep a straight face when someone tells a funny joke.
McGrawhill's American Idioms And Phrasal Verbs
2 general:: see KEEP A STRAIGHT FACE.
American Heritage Idioms