A person who works with or maintains tubs, or historically, someone employed in brewing or manufacturing to manage large containers.
From tub (a container) + man. Compound words using 'man' for occupations are ancient English formations, especially common in medieval trade work.
Harriet Tubman, the famous abolitionist, was born with the surname 'Ross' but her married name 'Tubman' comes from her husband John Tubman—yet history sometimes confuses her occupational name origins with her actual legacy!
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