What part of speech is the word in italics

Shelly and her beautiful dance throughly captivated the audience

As there are no words in italics, here is the list of all the words in this sentence together with parts of speech:

Shelly - a noun which represents person's name (proper noun)

and - a conjunction

her - an adjective (possessive form of she), also called possessive determiner

beautiful - an adjective (describes the noun 'dance')

dance - a noun

thoroughly - an adverb that modifies the verb 'captivated'

captivated - a verb (past tense of 'to captivate')

the - a definite article

audience - a noun