Several common phrases use the word less.

In less than no time

If you do something in less than no time, you do it very quickly.

• Although they managed to take him to hospital in less than no time, they couldn’t save his life.
• She cleaned up the mess in less than no time.

Less and less

Used to refer to something that gradually gets smaller in amount or degree

• Farming is growing less and less profitable.

Less of

Used to ask someone to stop doing something

• We’ll have less of that rudeness, please. (Used to ask someone to stop behaving rudely.)

Less than

Used before a number or amount to say that the actual number or amount is smaller than that.

• It was the second tragedy to strike their household in less than one month.
• A decent laptop costs less than $300 these days.

Less than + adjective

Less than can be followed by an adjective.

• Theirs was obviously a less than perfect marriage. (= Their marriage was not at all perfect.)
• The teacher said that she was less than satisfied with our performance. (= She was not at all satisfied with our performance.)

No less

Used for emphasizing that the person or thing you are talking about is very important

• She received the award from the President, no less.

No less than

• The applicants should have scored no less than 90% percent marks in the entrance examination.

Nothing less than

Used for emphasizing how important or serious something really is

• Their eagerness to help was nothing less than miraculous.