no
The noun is meeting, subject of the sentence.
appositive
The word 'attended' is the past participle, past tense of the verb to attend.The abstract noun forms of the verb to attend are attendance and the gerund, attending.
The noun 'high school' is a singular, common, compound, concrete noun; a word for a school attended after primary or elementary school, and after middle school; a word for a thing.
no "attended" is an adjective
We attended the wake for the deceased last Monday evening.
Attended is the past tense of the verb attend.
the word "all" is not a proper noun. It is a pronoun used to refer to multiple people collectively.
The plural form of the noun 'seminar' is seminars.
The past tense of "attendees" is "attended." In English, regular verbs typically form their past tense by adding "-ed" to the base form of the verb. Since "attendees" is a noun, the corresponding past tense verb form would be "attended" when referring to people who attended an event or gathering.
I think it is noun but I would have it checked
The word cheerful is an adjective, a word that describes a noun. The noun form is cheerfulness.