nonperiodic
/ˌnɑnpɪriˈɑdɪk/
adjective
- Not occurring at regular intervals; not repeating in a predictable pattern.
- The machine issues nonperiodic alerts that confuse the operators.
- Nonperiodic signals are harder to analyze than regular ones.
- The comet's orbit is nonperiodic, so it may not return for thousands of years.