资料来源 : pyDict

周期地

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Periodically \Pe`ri*od"ic*al*ly\, adv.
   In a periodical manner.

资料来源 : WordNet®

periodically
     adv : in a sporadic manner; "he only works sporadically" [syn: {sporadically}]