A dock laborer or stevedore, particularly in Scottish or Northern English ports; a person who works at the docks.
From 'dock' plus '-mackie' (a Scots/Northern English diminutive or familiar suffix, possibly related to 'mack' meaning friend or mate). This is a regional, colloquial term.
Dockmackie is pure working-class Scottish slang—the kind of word you'd hear on the docks of Glasgow or Edinburgh, showing how every port developed its own vocabulary for the people who did the heavy labor.
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