subsidence
suhb sahy duhns
- n an abatement in intensity or degree (as in the manifestations of a disease)
 - n a gradual sinking to a lower level
 - n the sudden collapse of something into a hollow beneath it
 
- Whatever the cause, natural subsidence is extremely slow and almost imperceptible.
 - Historically, that subsidence has been counteracted by sedimentation: new silt, sand and clay that are deposited when the river floods.
 - Historically, that subsidence has been counteracted by sedimentation: new silt, sand and clay that are deposited when the .