aperiodic /ā-pē-ri-odˈik/

1. Not periodic
2. Highly damped and coming to rest without oscillation (physics)

• union shops
• union suit
• union suits
• union territories
• union territory
• uniparous
• unipartite
• uniped
• unipeds
• unipersonal
• uniplanar
• unipod
• unipods
• unipolar
• unipolarities
• unipolarity
• unipotent
• unique
• uniquely
• uniqueness
• uniquenesses
• uniquer
• uniques
• uniquest
• uniramous