Prov. The first people to arrive will be able to get the best choices. You can't reserve a seat at the movie theater; it's strictly first come, first served.We should get to the book sale as soon as they open; it's first come, first served.
something that you say which means that the people who ask for something first will be the ones who get it, when there is not enough for everyone We've got ten cheap computers on offer. It's first come, first served.
Those who precede others will have their needs attended to earliest, as in So many people showed up that we may not have enough food to go around, so let it be "first come, first served ." The idea is very old, but the first recorded use of this precise phrase was in 1545. Also see early bird catches the worm.