aspheric /ə- or ā-sferˈik/ or aspherical /-i-kəl/

1. Not spherical
2. (of a surface) not forming part of a sphere

• treadled
• treadler
• treadlers
• treadles
• treadling
• treadlings
• treadmill
• treadmills
• tread on air
• tread on eggshells
• tread on someone's corns
• tread on someone's heels
• tread on someone's toes
• tread on the neck of
• treads
• tread the boards
• tread water
• treadwheel
• treadwheels
• treague
• treagues
• treas.
• treason
• treasonable
• treasonableness