сталкер

Etymology
The word was coined by the Strugatsky brothers for their novel "Roadside Picnic" (1972), as an allusion to Rudyard Kipling's character Stalky from the "Stalky & Co." stories and the. Ста́лки was well remembered by the Strugatskys from their childhood, when they read the stories in Russian translation. In the "Roadside Picnic", сталкер was a common nickname for men engaged in the illegal trade of prospecting for and smuggling of alien artifacts from the mysterious and dangerous "Zone".

Noun

 * 1)  stalker a person who stalks game (see usage notes)
 * 2) any person, whose occupation or activity is dangerously similar to those of characters from "Roadside Picnic".

Usage notes

 * It's a traditional translation, although not very accurate in meaning and connotations and it's seldom used in the sense of "stalker".
 * The term was popularised by 1979 Andrey Tarkovsky's (Андре́й Тарковсќий) movie with the same name - Stalker (Russian: Ста́лкер).
 * The English term "stalker" (a person who secretly follows someone, sometimes with unlawful intentions) is usually described as or