From <span class="searchmatch">Proto</span>-Indo-European *h₃érdʰ-u-s, from *h₃erdʰ- + *-us. Cognate with Latin arduus. IPA(key): /ˈɑr.du.ɣɑz/ *<span class="searchmatch">ardugaz</span> steep Old Norse: ǫrðugr Icelandic:...
*h₃érdʰ-u-s ~ *h₃érdʰ-éw-s *h₃érdʰu-ko-s <span class="searchmatch">Proto</span>-<span class="searchmatch">Germanic</span>: *<span class="searchmatch">ardugaz</span> (see there for further descendants) *h₃r̥dʰ-ō-s <span class="searchmatch">Proto</span>-Italic: *arðōs Latin: arbor, arbōs (see...