nimium

Nimium is the neuter of nimius doing adverbial work, and it keeps enough of its noun life to take a partitive genitive: nimium vini, too much wine, literally "too much of wine". Nimis sits beside it with the same meaning and most authors use them interchangeably.

The trap is tone. With an adjective, nimium does not always criticise. Nimium felix can be "all too fortunate", with a shadow over it, or simply "very fortunate" with no complaint at all, and poets exploit the ambiguity. Only the context tells you whether the writer is warning you or just intensifying.