the world > physical sensation > cleanness and dirtiness > dirtiness > dirt > dirtiness or soiling with specific kinds of dirt > be or become dirty or soiled with specific kinds of dirt [verb (intransitive)] > dirty with excrement (3)
intransitive. To void excrement, to defecate. Usually of animals, now typically with reference to dogs leaving excrement on paths, pavements, etc…
‘To befilth one's breech’.