greenkeeper
noun
green·keep·er ˈgrēn-ˌkē-pər 
variants or greenskeeper
ˈgrēnz-ˌkē-pər
: a person responsible for the care and upkeep of a golf course
Example Sentences
Recent Examples on the Web As a college student, Doak spent a year of independent study in the UK and Ireland, which included a summer caddying at the Old Course and also routinely picking the brain of its resident greenkeeper. 
Shaun Tolson, Robb Report, 2 July 2022 The heavens opened once more towards the conclusion of Sunday's play with greenkeepers forced to mop up standing water on the 18th green before the playoff could begin. CNN, 17 Sep. 2017
Shaun Tolson, Robb Report, 2 July 2022 The heavens opened once more towards the conclusion of Sunday's play with greenkeepers forced to mop up standing water on the 18th green before the playoff could begin. CNN, 17 Sep. 2017 Word History
First Known Use
circa 1730, in the meaning defined above