'barger' originates from English by adding the agentive suffix '-er' to 'barge', which itself comes from Old French and Medieval Latin.

'barger' formed from the base word 'barge' (from Old French 'barge', Medieval Latin 'barca') with the English suffix '-er' to denote an agent, producing the modern English 'barger'.

Initially, the root 'barge' meant 'a small boat' (from Latin 'barca'); adding '-er' created 'barger' meaning 'one who works on or operates a barge'. Over time a secondary informal meaning developed for someone who 'barges in' or intrudes.