Sentence:  In the following year her father undertook to give a course in Hebrew theology to Johns Hopkins students , and this brought to the Szold house a <WSD>group</WSD> of bright young Jews who had come to Baltimore to study , and who enjoyed being fed and mothered by Mamma and entertained by Henrietta and Rachel , who played and sang for them in the upstairs sitting room on Sunday evenings . 
Meaning of the word marked with <WSD> tags:  any number of entities (members) considered as a unit