fiducial UK /f(a)ɪˈdjuːʃ(ɪ)əl/US /fəˈd(j)uːʃəl/noun 3adjective 2forms 3 noun3 •In photography, a familiar reference object used to show size or scale, such as a ruler or a coin; a fiducial marker. •In manufacturing, a small mark on a circuit board used to align components; a fiducial point. •A pattern used in a QR code or similar to aid the electronic reader with determining its alignment. adjective2 •Accepted as a fixed basis of reference.Rulers and coins make good fiducial markers in photographs. •Based on having trust. formsfiducials · more fiducial · most fiducial