Chemical sprayer
From Memory Alpha, the free Star Trek reference.
A chemical sprayer is a type of device used to apply chemicals, in the form of a mist, such as weed spray.
During a rescue mission on Phylos in 2269, the landing party, James T. Kirk, Hikaru Sulu and Leonard McCoy, came armed with chemical sprayers containing McCoy's home brewed version of his great-great-grandfathers weed spray, which they used to neutralize attacking swoopers, and aid in their rescue of Spock. (TAS: "The Infinite Vulcan")
