more than; even more than
Follows a noun and emphasizes that something exceeds the standard set by that noun. Often used in comparisons like 'more than ever' or 'more than usual'.
今年の夏は例年にも増して暑い。
This summer is even hotter than usual.
彼女は前にも増して美しくなった。
She has become even more beautiful than before.
以上に also means 'more than', but にも増して carries a nuance of exceeding expectations or a previous standard, often with emotional emphasis.
A fixed expression combining the particle に, the particle も, and the て-form of the verb 増す (to increase). Literally 'even by increasing', it grammaticalized into an adverbial phrase meaning 'even more than'.