ditch; drain; groove; tread; gap (between people, countries, etc.); gulf
brown rat (Rattus norvegicus); common rat; dark grey (colour, color); dark gray; secret evil-doer
boards covering a ditch (drainage, sewage, etc.); grassroots (e.g. campaign); door-to-door; on the ground
ditch with running water; drainage channel
to throw down the drain; to waste
cleaning out mud from a ditch or drain
grassroots sales; door-to-door marketing
Chinese pond mussel (Sinanodonta woodiana)
Sphaerium japonicum (species of fingernail clam)