Resorcinol (R), Semicarbazine (S) and Formaldehyde (F) were taken as starting materials for synthesis of new terpolymer which has been abbreviated as ‘RSF-III’. Acid catalysed condensation polymerization method was adopted for the synthesis. This terpolymer was characterized using modern techniques like FTIR, 1H-NMR, XRD and SEM. On the basis of physicochemical and spectral evidences the most possible chemical structure has been elucidated for the novel polymer. The number average molecular weight of this polymer has been determined with the help of conductometric titration method in non aqueous media. The applicability of this novel polymer under investigation towards its biological (antibacterial) activities has been studied against standards. The experimental biological activities have been compared to draw final conclusion for microbs like E. coli, C. albicans, S. aureus and P. aeruginosa. The polymer under present investigation has been found to possess very good biological activities for above quoted microorganisms.