the smallest amount of something or number of things that is possible or necessary [≠ maximum]
a minimum of two hours/£1000 etc
The judge recommended that he should serve a minimum of 12 years.
He achieved enviable results with the minimum of effort.
absolute/bare minimum (=the very least amount or number)
Prison inmates are kept in tiny cells, with the bare minimum of furniture.
keep/reduce something to a minimum
She had reduced her consumption of fat and sugar to an absolute minimum.
used to say that if nothing else is done, this one thing should be done:
At a minimum, we must recruit two new teachers.