A resource allocation scheme (usually for memory). Best Fit tries to determine the best place to put the new data. The definition of 'best' may differ between implementations, but one example might be to try and minimise the wasted space at the end of the block being allocated - i.e. use the smallest space which is big enough.
By minimising wasted space, more data can be allocated overall, at the expense of a more time-consuming allocation routine.
Compare First Fit.
Megan: So the danger of price controls is that you forfeit the opportunity to get a best fit.
Thus, my dear pupil, will you best fit yourself for the duties of a student and of a teacher.
In other words, a deference to such qualities as can best fit them to get on in the world, and make the most money!
It was only to last 'till we shall have seen which place of residence is best fit for old age, which is already knocking'.
I need not say that the real education is that which will best fit a man for performing well his duties in life.
As fruit matures, the changes it undergoes are such as best fit for consumption and digestion.
The sons had no taste for books; they have a very good taste for wine and cigars, and have undertaken what they are best fit for.
He knows just what study and training each one ought to pursue in order to best fit himself for that vocation.
Before mixing materials select the pans that will best fit the oven.
We must leave our readers to decide for themselves what theory will best fit as an explanation of this strange and true story.