This page contains information regarding Star Trek: Lower Decks, and thus may contain spoilers.
A groundskeeper was a worker responsible for the maintenance of a property's landscape architecture and other arboreal or floral features.
Boothby was groundskeeper of Starfleet Academy in San Francisco for much of the 24th century, and was known to eschew the use of herbicide in favor of more traditional gardening techniques such as pulling weeds by hand. (TNG: "Final Mission", "The Game", "The First Duty"; VOY: "In the Flesh")
In 2381, there was a groundskeeper at Starbase 25 in the aviary, whom Ensign Beckett Mariner nearly ran over with her kart, but she swerved her vehicle just enough to miss him, causing herself and Brad Boimler to crash into a pond instead. Interestingly enough, the groundskeeper, who seemed to be quite advanced in years, appeared to be disappointed that he wasn't killed by the kart. (LD: "An Embarrassment Of Dooplers")