Specialized expressions indigenous to a particular field, subject, trade, or subculture

Verb

Idiom

Superlative

Dangling participle

Specialized expressions indigenous to a particular field, subject, trade, or subculture are known as idioms.

Verbs are words such as to do, to sing, etc. which show us what action the subject is performing. Superlative is the final form of an adjective, such as the best, the brightest. A dangling participle is a participle which doesn't refer to anything in a sentence. So, the correct answer has to be an idiom - an expression which symbolically refers to something, usually a professional field.