Collective noun
List of collective nouns

• List of collective nouns by subject A-H
• List of collective nouns by subject I-Z

Notes:
The phrase "An abomination of monks" is frequently cited as a legitimate collective noun for monks. It is actually a misinterpretation of the title of a protestant treatise written by Jan Hus around 1400.

An "anthology of prostitutes" is a pun on "anthology of prose", as "pro" is a common contraction for prostitute in Britain and elsewhere.

The phrase "A court of kangaroos" is frequently thought to be legitimate, given the (quite unrelated) expression "a kangaroo court". There is no known evidence of its legitimacy as a collective noun, however.

A "ream of paper" - A ream is traditionally defined as 480 sheets (twenty quires of twenty-four sheets each); the more usual modern count is 500 sheets to the ream. This is more a measure of paper than a collective noun, however.