Wiktionary
n. A certain pyrethroid insecticide.
Wikipedia
Prallethrin is a pyrethroid insecticide. Prallethrin 1.6% w/w liquid vaporizer is a repellent insecticide which is generally used for the control of mosquitoes in the household. Marketed as a mosquito repellent by Godrej as "GoodKnight Silver Power" and SC Johnson as "All Out" in India. It is also the primary insecticide in certain products for killing wasps and hornets, including their nests. It is the main ingredient in the consumer product "Hot Shot Ant & Roach Plus Germ Killer" spray.
The World Health Organization published in 2004 that "Prallethrin is of low mammalian toxicity, with no evidence of carcinogenicity" and "is very toxic to bees and fish but of low toxicity to birds."