What is the definition of the word but?

but/bət/

Preposition: Except; apart from; other than: "in Texas, we were never anything but poor"; "I trusted no one buthim".

Adverb: No more than; only: "he is but a shadow of his former self".

The Word "but" is defined as a conjunction used to state a contrast of a situation. For example, the food is placed on the table to cool but it may still be hot.