to make a definite choice or come to a firm conclusion in a situation where more than one option or possibility is open
He decided on the blue shirt
to make a judgment
She decided in favour of the defendant
(often + to/that) to make a choice or come to a conclusion about (something)
I decided to go by bus
They decided that they couldn't afford a holiday
to influence (somebody) to make a choice or resolution
In the end, her screaming decided me and I left the room
to settle the outcome of (something)
Her goal decided the match
decidable adj
[Middle English deciden via French from Latin decidere to cut or fall off, from de- + caedere to cut]