completely and without qualification; used informally as intensifiers
"an absolutely magnificent painting"
"a perfectly idiotic idea"
"you're perfectly right"
"utterly miserable"
"you can be dead sure of my innocence"
"was dead tired"
"dead right"
in a perfect or faultless way
"She performed perfectly on the balance beam"
"spoke English perfectly"
"solved the problem perfectly"
With perfection.
"The cake came out of the oven perfectly, rising evenly and smelling like fresh vanilla."
In plain English: Perfectly means doing something exactly right without any mistakes at all.
"She sings perfectly in tune with the melody."
Usage: Use "perfectly" to describe an action done with complete accuracy or flawlessness, such as solving a problem without error. Avoid using it simply to mean "very" when describing adjectives like good or nice, as that is often considered incorrect in formal writing.
Perfectly is formed by adding the suffix "-ly" to the word perfect. This construction simply turns the adjective into an adverb meaning "in a perfect manner."