Subside (5)

(Other definitions for abate that I've seen before include "Lose intensity" , "Subside like storm" , "(Flood) recede" , "Reduce" , "Become less in intensity" .)

(Other definitions for collapse that I've seen before include "Fall down as from weakness" , "Founder" , "Abrupt failure of function" , "fold" , "Fall or disintergrate" .)

(Other definitions for settle that I've seen before include "Come to an agreement about something" , "Resolve or reach an agreement" , "Colonise the bench" , "Get comfortable" , "Become established in permanent way, like pioneer" .)

(Other definitions for ebb that I've seen before include "Receding movement, as of a tide" , "Flow outwards" , "Initially Mrs Browning's" , "Not to wax" , "Outward flow of the tide" .)

(Other definitions for sag that I've seen before include "Drop" , "Subsidence" , "Sink, hang down" , "fall" , "Droop, sink in the middle" .)

(Other definitions for sink that I've seen before include "Droop, submerge" , "place of iniquity?" , "Drop in the ocean?" , "Basin - scupper" , "Scene of iniquity or washing up" .)