Flock is a collective word for a group of something, normally animals. I saw a flock of sheep (many sheep in one area). There can also be a church flock, a group of members who attend one church. http://dictionary.reference.com/browse/flock I'm suprised it was not in the dictionary. Playgrounds are where children play, normally at A school. http://dictionary.reference.com/browse/playground?s=t

"Flock" means a group animals or birds of one kind travelling, feeding or resting together. "Playgrounds" means an outdoor area provided for children to play on, especially at a school or public park.

Useful dictionaries http://www.merriam-webster.com http://dictionary.cambridge.org flock noun \ˈfläk\ Definition of FLOCK 1: a group of animals (as birds or sheep) assembled or herded together 2: a group under the guidance of a leader; especially : a church congregation 3: a large number http://www.merriam-webster.com/dictionary/flock playground noun play·ground \-ˌgrau̇nd\ 1 : a piece of land used for and usually equipped with facilities for recreation especially by children 2 : an area known or suited for activity of a specified sort http://www.merriam-webster.com/dictionary/playground