[TA] a broad convolution on the convexity of the frontal lobe of the cerebrum between the inferior frontal sulcus and the sylvian fissure; divided by branches of the sylvian fissure into three parts: opercular part [TA] (pars opercularis [TA]), triangular part [TA] (pars triangularis [TA]), and orbital part [TA] (pars orbitalis [TA]); the first two constitute a portion of the frontal operculum. SYN: gyrus frontalis inferior [TA], Broca convolution, inferior frontal convolution.