from one side to the other of a vessel at right angles to the keel
athwartships in American English
(əˈθwɔrtˌʃɪps)
adverb
Nautical
from one side of a ship to the other
Word origin
[1710–20; athwart + ship + -s1]This word is first recorded in the period 1710–20. Other words that entered Englishat around the same time include: bother, o'clock, offshore, rewind, tint-s is a native English suffix used in the formation of adverbs. Other words that usethe affix -s include: always, betimes, needs, unawares