The Collaborative International Dictionary of English v.0.48:
Slantwise \Slant"wise`\, Slantly \Slant"ly\, adv. In an inclined direction; obliquely; slopingly. [1913 Webster]WordNet (r) 3.0 (2006):
slantwise adv 1: at a slant; moving or directed in a slantwise position or direction [syn: slantwise, slantways]