Step 1 : Introduction to the question "What is one of the terms used for a group of kangaroos?"
...The kangaroo is a marsupial from the family Macropodidae (macropods, meaning "large foot"). In common use the term is used to describe the largest species from this family, especially those of the genus Macropus: the red kangaroo, antilopine kangaroo, eastern grey kangaroo, and western grey kangaroo. Kangaroos are indigenous to Australia. The Australian government estimates that 34.3 million kangaroos lived within the commercial harvest areas of Australia in 2011, up from 25.1 million one year earlier. A kangaroo court is a court that ignores recognized standards of law or justice, and often carries little or no official standing in the territory within which it resides. The term may also apply to a court held by a legitimate judicial authority who intentionally disregards the court's legal or ethical obligations. Kangaroos are often colloquially referred to as "roos". Male kangaroos are called bucks, boomers, jacks, or old men; females are does, flyers, or jills; and the young ones are joeys. The collective noun for kangaroos is a mob, troop, or court.