Is the word amusement an abstract noun?

The Word 'amusing' is the present participle, present tense of the verb 'to amuse'. The present participle of the verb is also an adjective and a gerund (verbal noun), an abstract noun. Examples:

verb: Jason was amusing himself with war games when he should have been doing his English homework.

adjective: The amusing clown finally exited the circus tent after a long, but enjoyable performance.

noun: Amusing as he was to his classmates, he was not entertaining the teacher.