to choose something or someone after thinking carefully
Have you decided on a name for the baby?We've decided on a beige carpet for the dining-room.
phrasedecide upon !Decide upon is more formal than decide on and is mostly used in writing. decide on/upon sth/sb to choose something or someone after thinking carefully: In the end we decided on a small Italian restaurant.Have you decided on a date for your wedding yet?+ what/where/which etcFirst, you have to decide upon which subjects you like best.■ SIMILAR TO: settle on/upon