From Wiktionary, the free dictionary
From plane + -al.
planal (not comparable)
- Of or relating to a geometric plane.
2009 April 30, Anne Eisenberg, “Solar Tech: Not Just on the Roof Anymore”, in New York Times[1]:“Silicon does work well, but it’s always been the limitation that you make silicon devices on hard, rigid, planal surfaces,” Dr. Whitesides said.
