sessional adjective 1noun 1forms 1 adjective1 •Pertaining to a period, often an academic term or a sitting of a legislative body.CUPE 3902 is a labour union local representing sessional lecturers and teaching assistants (TAs) at the University of Toronto, Canada. noun1 •An instructor hired by a college or universities on a temporary basis.The sessionals’ Agreement was ratified on 1 April, 2005. formssessionals