adv. Naut. [f. as prec. + -s of adverbial genitive.] = prec. B.

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a. 1625.  Nomenclator Navalis (Harl. MS. 2301), s.v., Anie thing that is done or lies acrosse ye Shipp from one side to thother wee saie that it lies thwart ships.

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1718.  Steele, Fish Pool, 175. The depth of the arch of the deck thwartships is 4 inches.

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