To mime is to act out silently.
silently
creeps
The word silently *is* an adverb. The adjective form is "silent."
Another word for 'do' beginning with A is act.
The word is silentium.
more silently
Silently is an adverb. Many adverbs end in the prefix -LY.
cheeky
Noisily
Act
It is neither. The word silently is an adverb, the adverb form of the adjective silent.
Yes, it is the adverb form of the adjective silent.