The word precariously, like most words that end in -ly, is an adverb.
part of speech
Adjective
What part of speech is thaw
The part of speech for oscillate is verb.
An adjective is a part of speech.
He was balanced precariously on top of the fence. The rock was precariously balanced on the edge of the cliff.
The schoolbus balanced precariously on the edge of the cliff.
The boat rocked precariously when my sister jumped into it.
She clung precariously to the ledge, trying not to slip off the edge.
Dangerously
His book was balanced precariously on the edge of the table, with only half of it actually on the surface.
The girl was dancing precariously, as it seemed like she may fall off the edge of the stage. Luckily, she did not, and the show continued on.
part of speech
The part of speech for this particular word is a noun.
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath