An analytical approach has been taken into consideration to investigate shear wave propagation in a multiferroic composite FGPE/FGPM consisting of a functionally graded piezoelectric layer on a functionally graded piezomagnetic half-space. It is assumed that the interface in the composite is damaged mechanically, magnetically, or electrically. A well-known Wentzel–Kramers–BrillouinWKB asymptotic approach has been applied for the solution of the composite structure. Phase velocity has been calculated numerically for magneto-electrically open and short cases. Graphs have been plotted with respect to phase velocity and wavenumber for unraveling the effect of different parameters such as mechanical imperfection parameter, gradient parameters, and magneto-electro mechanical coupling parameters. These parametric studies yield mainly three conclusions: (a) The presence of mechanical imperfection parameter remarkably enhances the phase velocity, depending upon the values of wavenumber. (b) Phase velocity rises and falls for layer and half-space with the rising value of gradient parameters, while keeping the rest parametric values fixed, respectively. (c) The magnetomechanical coupling parameter increases the phase velocity for both magneto-electrically open and short cases, but the electromechanical coupling parameter decreases the phase velocity for both open and short cases. The present results have relevant applications in the non-destructive testing and evaluation of composite materials like FGPE/FGPM.