as an adverb (before an adjective or another adverb): I’m feeling rather tired.She’s been treated rather badly. (before a verb): He rather enjoys telling other people what to do. (as an answer word): ‘Would you like to come for a ride?’ ‘Rather!’
as a predeterminer (followed by ‘a’): This is rather a good wine.
in the conjunction phrase rather than: It would be better to make a decision now, rather than leave it until later.
as a way of showing how a sentence is connected to what has already been said: His purpose was not so much to attack his rivals. Rather, it was to defend his own position.