This work presents the design and the corresponding stability analysis of a model free velocity observer formulation for nonlinear systems modeled by Euler-Lagrange formulation. The observation gains of the proposed formulation are tuned online according to an update algorithm removing the burden of observation gain tuning. Lyapunov based arguments are applied to prove the overall system stability. Performance of the observer proposed is illustrated via extensive simulation studies. Experimental studies are also utilized to demonstrate the viability of the proposed formulation.