A thing changes in a sense associated with Russell (hence, at Cambridge) if it satisfies a description at one time that it does not satisfy at another. However, some such changes are ‘merely’ Cambridge changes: if you outgrow me, then I satisfy the description of being as tall as you at one time, and I do not satisfy the description at another. So, by the Cambridge criterion, I have changed, but I need have undergone no robust or substantial change, for I may have stayed at exactly the same height. The term was introduced by P. T. Geach (Logic Matters, 1972); a possible application of the notion is to make the unchanging (substantial) nature of God compatible with his (merely Cambridge) changing relations to the temporal world.