backgain noun 3adjective 2forms 3 noun3 •(dialect, UK) A relapse. •(dialect, UK) A relapse in illness. •(dialect, UK) A decline; consumption. adjective2 •(dialect, UK) Receding; going back. •(dialect, UK) Not thriving in health or in worldly concerns. formsbackgains · more backgain · most backgain