Also found in: Dictionary.
decide on (someone or something)
To choose someone or something, usually after a period of deliberation. Yes, Holly was a strong candidate, but we ultimately decided on someone else for the job opening. After agonizing over the menu, I finally decided on mint chocolate chip ice cream.
decide (up)on someone or something
to choose someone or something; to make a judgment about some aspect of someone or something. (Upon is formal and less commonly used than on.) Will you please hurry up and decide upon someone to vote for? I decided on chocolate.
decide onor decide upon
To choose something or someone after deliberation: We decided on green as the color for the nursery. I've decided upon the red shoes; you can put the black ones back.