Friction is anything that acts as a barrier when attempting to perform an action. Friction acts as a demotivator to move beyond the status quo. An example of friction is a long, tedious application form to enroll in a healthcare plan.
Relevant Academic Papers
Kling, J. R., Mullainathan, S., Shafir, E., Vermeulen, L. C., & Wrobel, M. V. (2012). Comparison friction: Experimental evidence from Medicare drug plans. The quarterly journal of economics, 127(1), 199-235.