crosswise

adjectives

lying or extending across the length of a thing or in a cross direction
"a crosswise street"; "the crosswise dimension"
antonym
is similar to
extending or lying across; in a crosswise direction; at right angles to the long axis
"cross members should be all steel"; "from the transverse hall the stairway ascends gracefully"; "transversal vibrations"; "transverse colon"
is similar to
representing a plane made by cutting across something at right angles to its length
"cross-section views of the neck"
in the shape of (a horizontal piece on) a cross
is similar to
parallel to or in the plane of the horizon or a base line
"a horizontal surface"

adverbs

not in the intended manner
"things are going crosswise"
transversely
"the marble slabs were cut across"