Adverb, : less exact. ,He could barely pay for his own lodging, much less for that of his friend. ,He is nothing less than a thief.    From Dictionary.com. 

Adjective, : less money; less speed. ,no less a person than the manager. ,less than a dozen.    From Dictionary.com. 

Noun : Hundreds of soldiers arrived, but less of them remained. ,He was tortured for less.    From Dictionary.com. 

Preposition : a year less two days; six dollars less tax.    From Dictionary.com.