unpeg
Word family
Synonym discussion
Sense: verb/1
Unpeg is the most specific of these words — it only describes ending a fixed exchange rate between currencies. Decouple and delink are broader: you can decouple two issues in an argument or delink a train carriage, while unpeg always concerns money. Float names the state that follows unpegging (a currency floats after being unpegged), but it does not refer to the act of breaking the peg itself. Detach is the most general term and can describe any physical or abstract separation. For example, 'The central bank unpegged the peso' (correct, financial context) versus 'The central bank detached the peso from the dollar' (unusual — sounds physical rather than financial).
Etymology
Formed from the prefix 'un-' (meaning 'to reverse or undo') and 'peg' (a small pin or bolt used for hanging or fastening). The literal sense — removing something from a physical peg — appeared in the 19th century. The financial meaning emerged in the mid-20th century as countries began moving away from fixed exchange rate systems, especially after the collapse of the Bretton Woods agreement in the early 1970s.
First known use
1602
1602, in the meaning defined at sense 1