Regressive assimilation is assimilation of segment S1 to segment S2 where S1 precedes S2.:

Examples

Lat. ad-similatio → assimilatio.

In Engl. bank, the place of articulation of /n/ is adjusted to the velar one of /k/.

In MHG hündi, plural of hund 'dog', the ü results from regressive assimilation to the final i.