most
In Italian, 'più' is used for both more and most. The context determines whether it means 'more' or 'most'. It's usually used as an adverb. For example, 'Il mio libro è il più interessante' means 'My book is the most interesting'.
Today is hotter than yesterday
In this phrase, 'più' is used to denote comparability meaning 'more than' or 'hotter than'.
I want more pizza
This phrase demonstrates the use of più as 'more' in the context of wanting increased quantities of something, in this case, pizza.
It can't rain forever, sooner or later the most beautiful sun always arrives.
This sentence shows the use of 'più' as 'most' to highlight a superlative degree in describing 'the most beautiful sun'.