Destressing

Destressing is a type of rule which deletes either a stress or the constituent of which this stress is the head (i.e. a foot). The footless syllable(s) undergo(es) stray adjunction. Destressing rules adjust the representation assigned by stress assignment rules.

Example
In English a stress on a light syllable (i.e. a foot) assigned by the stress rules is removed by a destressing rule: /bÃ nÃ¡na/ /banÃ¡na/. The application of the destressing rule explains that the vowel of the first syllable can reduce (cf. [bana¡na]), whereas this is not allowed in /bÃ ndÃ¡na/ -/-&gt; *[b@ndÃ¡na] which has a heavy syllable.

Link
Utrecht Lexicon of Linguistics