<span class="searchmatch">sēmicirculī</span> inflection of sēmicirculus: nominative/vocative plural genitive singular...
<span class="searchmatch">sēmicirculīs</span> dative/ablative plural of sēmicirculus...
From sēmi- + circulus. sēmicirculus m (genitive <span class="searchmatch">sēmicirculī</span>); second declension semicircle Second-declension noun. “semicirculus”, in Charlton T. Lewis...