x1 is a rodent [member of eutherian mammal Rodentia] of subtaxon/type/genus/species/breed/variety x2
Meant for any rodent in general (more general than ratcu, smacu). See also: ratcu, smacu, ronte. If ronte is accepted as an official (non-experimental) gismu, this word would be dispreferred to ronte or rontnrodentia; presently, whether only Rodentia or any "small, scurrying mammal" can be so-referred is vague (although probably preference is the strict sense of only Rodentia).