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definitions

jack block

noun Nautical.

a block used in raising or lowering a topgallant yard.

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Nearby words

  1. jacaré,
  2. jacinth,
  3. jack,
  4. jack arch,
  5. jack bean,
  6. jack chain,
  7. jack crevalle,
  8. jack crosstree,
  9. jack frost,
  10. jack in

Origin of jack block

First recorded in 1785–95
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019