mucoid n any of several glycoproteins similar to mucin a relating to or resembling mucus a mucoid substance Usage(s) Men with chlamydia can experience a burning sensation during urination and a mucoid discharge, but their illness is often diagnosed as gonorrhea. Chlamydial infections usually produce mild but recognizable symptoms in men: pain during urination and a clear, watery mucoid discharge. Synonym(s) mucoidal