Real Dictionary

-less
suffix: -less is added to nouns in order to form adjectives that indicate that someone or something does not have the thing that the noun refers to.

-less in American English
without, lacking
suffix: an adjective suffix meaning “without” (childless; peerless), and in adjectives derived from verbs, indicating failure or inability to perform or be performed ( resistless; tireless)

-less in British English
suffix forming adjectives: without; lacking

less
determiner: You use less to indicate that there is a smaller amount of something than before or than average. You can use 'a little', 'a lot', 'a bit', ' far', and 'much' in front of less.

less in American English
little
to a smaller extent, amount, or degree

less in British English
determiner