Entrenchment consisting of an additional interior fortification to prolong the defense

The reduction of expenditures in order to become financially stable

The act of laying off an employee or a work force

Retrenchment is a technique associated with Formal Methods that was introduced to address some of the perceived limitations of formal, model based refinement, for situations in which refinement might be regarded as desirable in principle, but turned out to be unusable, or nearly unusable, in practice.