Orbital

Synonyms for orbital
adj at fixed intervals

yearly
recurrent
intermittent
annual
occasional
repeated
regular
routine
sporadic

periodical
alternate
cyclical
daily
infrequent
perennial
rhythmic
serial
spasmodic

cyclic
isochronal
isochronous
seasonal
monthly
recurring
weekly
at various times
centennial

epochal
every once in a while
every so often
fluctuating
hourly
on certain occasions
on-again-off-again

Antonyms for orbital

infrequent
unusual
continual

lasting
permanent
sporadic

variable
constant
irregular