atta (ata-) (4) prep. "across, over, lying from side to side" (VT49:32; it is not quite clear whether this is a Quenya word or not)
Quenya
arta
across, athwart
atta
across, over, lying from side to side
langa-
to cross, go over, pass over
langa- vb. "to cross, go over, pass over" (VT49:65)
arta (4) prep. "across, athwart" (LT2:335), perhaps rather olla in Tolkiens later Quenya.