the world > action or operation > behaviour > customary or habitual mode of behaviour > do habitually [verb (reflexive)] > accustom oneself > become accustomed (3)
transitive (reflexive). = acclimatize, v. 3.
transitive (reflexive). To grow or become habituated to a new climate or environment.
to shake down: intransitive and reflexive, to settle down, to accommodate oneself to circumstances, a condition, position, etc.