smallest in size, amount, degree, etc.; slightest

He gave the least amount of money of anyone.

lowest in consideration, position, or importance.

something that is least; the least amount, quantity, degree, etc.

South Midland U.S. the youngest in a family or group.

to the smallest extent, amount, or degree

That's the least important question of all. He talks least.

at least

at the lowest estimate or figure

The repairs will cost at least

at any rate; in any case

You didn't get a good grade, but at least you passed the course. Also, at the least.

not in the least

not in the smallest degree; not at all

I am not in the least concerned about the outcome of the World Series.

adjective

most

adjective

atomic , bottom , entry-level , feeblest , fewest , finical , first , gutter , infinitesimal , last , lowest , meanest , microcosmic , microscopic , minimal , minimum , minute , minutest , molecular , most trivial , nadir , next to nothing , niggling * , piddling * , poorest , second , short-end , third * , tiniest , trivial , unimportantnotes:leased means to use or allow someone else to use something for an agreed period of time in exchange for a payment; least is lowest in importance , rank , magnitude , or degree , shortest , slightest , smallest , unimportant