Definition of Tom Thumb in US English:

Tom Thumb

noun

  • usually as modifier A dwarf variety of a cultivated flower or vegetable.

    ‘Tom Thumb lettuce’

Origin

Late 19th century: from the name of the hero of a children's story, a plowman's son who was only as tall as his father's thumb.

Pronunciation

Tom Thumb

/ˌtɑm ˈθəm//ˌtäm ˈTHəm/