Synonyms for Recurrent:

adj.

all (adjective)
perennial, repeated.
frequent (adjective)
frequent, general, incessant, commonplace, everyday, Familiar, prevalent, common, repeated, customary, usual, habitual, often, many, monotonous.
habitual (adjective)
common, cyclic, habitual, ordinary, normal, traditional, chronic, conventional, accustomed, standard.
relapsed (adjective)
recessive, recidivist, lapsed, Relapsed, regressive.
repeated (adjective)
repeated.

n.

Isochronous, Isochronal, like clockwork, cyclic, repetition, periodical. again (noun)
repeatedly, renewed, yet again, ad infinitum, over, again.

Other synonyms:

cyclic, Isochronous, Isochronal. again
again, over, renewed, ad infinitum.
periodic
periodical.