(inorganic chemistry) nitrogen dioxide

two-wheeled vehicle, (especially) motorcycles / bicycle

a female given name

double negative

a surname

(history, socialism) the Second International

second party, after-party

a quadratic equation

twelfth day of the month

Used other than figuratively or idiomatically: see 二, 枚, 目. (the second sheet or other flat thing) / a handsome male character, especially one that gets involved in a romance during the story