simper

/ˈsɪmpər/
verb
  1. To smile in a silly, self-conscious, or affected way.
    • She would simper whenever the teacher complimented her drawing.
    • The actor simpered at the audience during the curtain call.
    • He simpered nervously when asked about his new haircut.
Antonyms
noun
  1. A silly, self-conscious, or affected smile.
    • Her simper made it clear she was embarrassed by the attention.
    • The politician's simper did not convince the reporters.
    • He gave a nervous simper before answering the question.