English: omnibus
Welsh: omnibws 
Subject: Cynllunio
English definition: Surveys conducted regularly by a research agency, but which can be sponsored by a number of clients who do not share the same data but who buy access to survey questions to meet their individual needs.
Welsh definition: Arolygon sy'n cael eu cynnal yn rheolaidd gan asiantaeth ymchwil, ond y gellir eu noddi gan nifer o gleientiaid nad ydynt yn rhannu'r un data ond sy'n prynu'r hawl i gael cwestiynau ar gyfer arolwg i ddiwallu eu hanghenion unigol..