'embargo' originates from Spanish, specifically the word 'embargo', where 'em-' (variant of 'en-') functioned as a prefix meaning 'in/on' or forming a causative, and the root related to Spanish 'bargo'/'bargar' (from earlier forms) meaning 'bar, hinder'.

'embargo' came into English in the early 17th century from Spanish 'embargo' and the verb 'embargar' (Old Spanish), which in turn derived from earlier Romance or Vulgar Latin formations meaning 'to block or seize'. The modern English noun 'embargo' and verb 'embargo' (with past/p.p. 'embargoed') developed from these entries.

Initially it meant 'a hindrance, seizure, or obstruction' (often of goods). Over time it specialized to mean an official prohibition or restriction (especially on trade, shipments, information, or publication) and the verb came to mean 'to impose such a prohibition'.