Is violently an abstract noun

No, the Word 'violently' is an adverb, a Word used to modify a verb, an adjective, or another adverb.

The adverb 'violently' is the adverb form of the adjective violent.

The related noun is violence.

Examples:

• The wind blew violently, causing a lot of damage. (adverb, modifies the verb 'blew')
• The drivers were in a violent argument over the fender bender. (adjective, describes the noun 'argument)
• Violence is not the way to solve problems. (noun, subject of the sentence)