retrenchyoudaoicibaDictYouDict
retrench: [16] Retrench originally meant literally ‘dig a new trench as a second line of defence’. It was borrowed from early modern French retrencher, a descendant of Old French retrenchier. This was a compound verb formed from the prefix re- ‘again’ and trenchier ‘cut off’ (source of English trench, trenchant, etc). The standard present-day sense of retrench, ‘cut back, economize’, first recorded in the 17th century, is a return to the underlying meaning of French retrencher.
=> trench, trenchant
retrench (v.1)youdaoicibaDictYouDict
1590s, "dig a new trench as a second line of defense," 1590s, probably a back-formation from retrenchment in the military sense. Related: Retrenched; retrenching.
retrench (v.2)youdaoicibaDictYouDict
"cut off, cut down, pare away" (expenses, etc.), 1620s, from obsolete French retrencher "to cut off, lessen, shorten" (Modern French retrancher, Old French retrenchier), from re- "back" (see re-) + Old French trenchier "to cut" (see trench). Related: Retrenched; retrenching.