Semi stitched implies either half stitched outfit in which styles are pre-constructed like shown in the image or has pre-defined neck styles, sleeve style on fabric with pre-defined sleeve length, neck depths & outfit length. In these type of apparels, either only side seams are left open which can be adjusted as per the bust size chosen.

Or it may have an unstitched fabric with pre-constructed back and neck design and sleeve border.In rare scenario, the length of the choli/lehenga and sleeves can be altered, if the design permits.