formenkreis
noun
for·men·kreis
ˈfȯrmənˌkrīs
plural formenkreise
-īzə
or formenkreises -īsə̇z
: a polytypic species (as of birds)
Word History
Etymology
German, literally, cycle of forms, from formen, plural of form (from Middle High German forme, from Latin forma) + kreis circle, cycle