'Crossjack' definitions:

Definition of 'crossjack'

(from WordNet)
noun
The lowermost sail on a mizzenmast [syn: crossjack, mizzen course]

Definition of 'Crossjack'

From: GCIDE
  • Crossjack \Cross"jack`\ (kr?s"j?k` or kr?"j?k`), n. (Naut.) The lowest square sail, or the lower yard of the mizzenmast. [1913 Webster]