2) This is a list of three or more items, usually separated by commas.

- Series.

Explanation:

As per the question, a list of three or more items separated by commas exemplifies 'series' in English grammar. This list of three items may include words or phrases, nouns or infinitives, etc. which are generally organized in a parallel manner to keep the ideas connected. To illustrate, let us look at some examples:

"Mr. George's estate would be disseminated into his wife, son, daughter-in-law, grandson, and daughter."

"We went to the park, played football, exercised for a while, and returned back home."

Thus, 'series' is defined as a list of three or more items separated by commas as demonstrated above.