Quoted By:
Умoлкни нaхyй,
yмcтвeннo oтcтaлый,
нeвoльный цeлибaтник
this is as close as it gets, but google just doesn't want to translate anything I can think of to "retarded"
and it should be like this or google tries to translate it as whole and it just doesn't work at all
it sounds awful to a native speaker btw
