periodic (adj.)

• alternate
• articulated
• ceaseless
• circling
• connected
• constant
• continual
• continued
• continuing
• continuous
• cyclic
• cyclical
• direct
• editorial
• endless
• episodic
• epochal
• even
• featureless
• fluctuating
• frequent
• harmonic
• haunting
• immediate
• incessant
• interminable
• intermittent
• isochronal
• isochronous
• iterative
• joined
• journalistic
• linked
• measured
• monotonous
• never-ending
• nonstop
• occasional
• oscillating
• oscillatory
• pendulous
• perennial
• periodical
• reciprocal
• recurrent
• recurring
• regular
• repeated
• repetitive
• resonant
• returning
• revenant
• rhythmic
• rotary
• round-the-clock
• running
• seamless
• seasonal
• serial
• serried
• smooth
• sporadic
• stable
• steady
• straight
• thematic
• ubiquitous
• unbroken
• unceasing
• undifferentiated
• undulant
• undulatory
• unending
• uniform
• uninterrupted
• unrelieved
• unremitting
• vacillating
• vibratory
• wavelike
• wavering
• wheeling