nonspiral
/ˈnɒnˌspaɪrəl/Definitions
1. adjective
not shaped like a spiral; not spiraling or curved in a spiral shape
“The nonspiral design of the staircase made it safer for users with mobility issues.”
2. noun
a galaxy or other celestial object that is not spiral in shape
“The astronomer studied the characteristics of the nonspiral galaxy in the distant universe.”