I. əˈ- adverb
Etymology: Middle English, adverb & preposition, from a- (I) + thwart
1.
a. : from side to side : across especially in an oblique direction : transversely
the line of probable advance runs athwart to the high chains of mountains — W.V.Pratt
b. : at right angles to the center line (of a ship)
2. : in opposition to the right or expected course : crosswise , awry
and quite athwart goes all decorum — Shakespeare
II. preposition
Etymology: Middle English
1.
a. : from side to side of : transversely over : across
a row of steppingstones set athwart the creek — Eden Phillpotts
b. : from side to side of the length, direction, or course of (a ship) : across
a fleet standing athwart our course
2. : in opposition to : contrary to
a procedure directly athwart the New England prejudices — R.G.Cole