Colin; Scottish mathematician (1698-1746). (Spelling changed from MacLaurin.)
Maclaurin is a lunar impact crater that is located in the eastern part 's near side. It lies just to the southeast of the small Mare Spumans, and to the northeast of the prominent crater Langrenus. To the east-southeast is Gilbert. The rim of this crater is perhaps unusual for the number of lesser craters attached to the exterior. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.