This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Occurring without periodicity; irregular.

adj. Physics Without periodic vibrations.

adj. That does not recur periodically

adj. That does not have a periodic vibration

adj. for which any return to it may occur at irregular times; not periodic.

Without periodicity.

adj. not recurring at regular intervals

"Some trajectory orbits are aperiodic, meaning that they do not repeat themselves on any time scales."

noncyclic    nonoscillatory   

periodic   

aperiodic galvanometer   

diapson    acicular    triiodide    monochromator    hand-cut    hydrogen-bonded    Waterford    1-in    tranq    pyroelectric