Herein, we adapted a quick, cost-effective, and an environmentally friendly biological method for the synthesis of Ag-NPs using silver nitrate solution as a precursor, and the aqueous leaf extract of Lespedeza juncea (Chinese lespedeza) was exploited to synthesize Ag-NPs. Various physiochemical characterization techniques were used to characterize the nanoparticles. The UV-spectrum revealed a resonance absorption peak at 428 nm, indicating successful synthesis of the nanoparticles. The EDX results indicated the presence of Ag, C, O, and Cl elements in biosynthesized Ag-NPs with elemental composition of 53.93%, 32.34%, 12.49%, and 1.23% respectively. The XRD analysis displayed the crystalline nature of the nanoparticles with face-centered cubic lattice. The FTIR spectrum confirmed the involvement of plant-based biological compounds as reducing and capping agents. TEM revealed quasi-spherical Ag-NPs of 50 nm or smaller in size. An insight of its biological activities reveals significant antimicrobial activities against S. aureus (14.1±0.76 mm), P. aeruginosa (11.50± 0.40 mm), E. coli (16± 0.95 mm), and the fungal strains Viz Candida albicans (14±0.80 mm), Aspergillus flavus (16.50±0.50 mm), Aspergellus niger (17± 0.86 mm) and afflicted 75% mortality to C. eligans. Furthermore, the Ag-NPs were found to be potent inhibitors of the enzymes; tyrosinase, urease, acetylcholinesterase, and butyrylcholinesterase with IC 50 values of 14.3±0.2 μg/mL, 19.5±1.1 μg/mL, 9.3±1.3 μg/mL and 32.65±1.9 μg/mL respectively. The overall outcome of the study suggests that L. jumcea mediated synthesized Ag-NPs hold the potential to be employed as a promising tool for their antibacterial, antifungal, nematocidal and for variety of enzymes inhibitory activities.