From Wiktionary, the free dictionary
ни (ni, “not”) + що (što, “what”). Ultimately from Proto-Slavic *ničьto.
ни́що • (níšto)
- nothing
- “нищо”, in Речник на българския език [Dictionary of the Bulgarian Language] (in Bulgarian), Sofia: Bulgarian Academy of Sciences, 2014
- “нищо”, in Речник на българския език [Dictionary of the Bulgarian Language] (in Bulgarian), Chitanka, 2010