Czech síra

← Proto-Slavic *sěra (inherited)

← Proto-Slavic *sěra (inherited(cs/zlw-ocs))

← Old Czech síra (inherited)

→ Czech sirka (suffix)

→ Czech sírový (suffix)

→ Czech síran (affix)

→ Czech sirovodík (affix)

→ Czech siřičitý (affix)

→ Serbo-Croatian sjera (cognate)