Isogonal is a 8 letter English word. It's valid Scrabble word worth 9 points. It's valid Words with friends word worth 12 points.
You can make 311 anagrams from letters in isogonal (agilnoos).
1855-60; Greek isogṓn(ios) equiangular (see iso-, -gon) + -al1
The former part is clearly on the isogonal where the declination is 0, the latter on the isogonal where it is 180.