Modified Newtonian dynamics (MOND) is a theory of gravity developed in 1983 by Mordehai Milgrom, offering an explanation for the same dynamics that motivates the concept of dark matter. It outlines a pattern in the force of gravity in which the force is weaker at longer distances. It is not widely accepted in astrophysics, but writeups of astrophysical experiments or observations which have the potential to provide evidence for it, show consistency with it, or contradict it do sometimes mention that.
Entropic gravity (or emergent gravity) is a 2007 theory developed by Erik Verlinde that bases a MOND-like gravity on string theory and hypothesizes a relation between gravity to entropy. It results in divergence from the usual gravitational formula at extremely small distances.