The Oxford Dictionary of Last Names esplains WORMUTH as a variant of Warmut, an old but very rare German personal name (not even listed in Seibicke's HDV!)
http://www.ancestry.com/learn/facts/fact.aspx?&fid=10&fn=&ln=Wormuth
The most likely translation of its first element seems to be "true" (German "wahr"). other possibiities are:
wara, "keep, pay attention"
warja, "defend"
warn, "warn"