mind my Russian is quite a bit rusty...but here goes...
when I don't know a word specifically but it contains a root similar to a word or verb that I do know, it often contains a similar meaning.
seeing this name without looking it up I would assume its related to the verb "Iskat'" meaning to search and nouns are often made from verbs, I believed in English grammar terms: adverbial nouns, the action of performing x...
therefore, the first assumption would be this names means "Search or Searcher"
yet the common given meaning seems to be "Spark" yet when I look verbs to spark or to ignite no verbs appear with similar form, unless perhaps it is very obscure and therefore not listed...
Mind not all Slavic-based languages are identical and do vary but they contain a lot of similarities in roots and such.
For someone who knows, what is the origin of this word?