periodic
peer-ee-OD-ikadjMeaning happening at regular intervals
Memory hook PERIOD-ic: like the bell every PERIOD. The school bell rings at the end of every class period, right on schedule. Its ringing is periodic.
The car needs periodic oil changes, one every five thousand miles, like clockwork.
In context The comet makes periodic visits to our skies, returning roughly every seventy-six years, so most people see it only once in a lifetime.
Similar regular, cyclical, routine, scheduled
Opposite irregular, random
From Greek periodos, “a going around, a cycle”: peri (around) + hodos (way).