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"action of lopping off or pruning," c.1600, from obsolete French retrenchement "a cutting off or out," from retrencher (see retrench (v.2)). Military sense is recorded from 1580s; see retrench (v.1).
retrenchment re·trench·ment (rĭ-trěnch'mənt)n. The cutting away of superfluous tissue.