subsidence
(noun)
noun
1. an abatement in intensity or degree (as in the manifestations of a disease)
Similar word(s): remission, remittal
Definition categories: event, abatement, hiatus, reprieve, respite, suspension
2. a gradual sinking to a lower level
Similar word(s): settling, subsiding
Definition categories: event, sinking
3. the sudden collapse of something into a hollow beneath it