One that is the lowest or smallest in importance, rank, magnitude, or degree: The dinner menu is the least of my worries tonight. The least you can do is to be polite.
at least According to the lowest possible assessment; not less than: waited at least an hour.
at least In any event; anyway: You might at least answer.
in the least At all: I don't mind in the least.
least of all Particularly not: Nobody cared, least of all the manager.