Can it be of Gipsy origin?
OK, I found that word “ikáč” was (or is) a dialectal form of “tkáč” (weaver) somewhere in eastern Slovakia and Zakarpattia Oblast in Ukraine. The word itself is of Slavic origin.
The name could come to Serbia and Croatia with the arrival of Slovaks and Rusyns.
In Vojvodina, Serbia they still speak their own dialects, which are official languages (among others) in the region.