persistent (adj.)
- abiding
- accordant
- adherent
- adhesive
- aged
- alike
- ancient
- antique
- archaic
- assiduous
- automatic
- balanced
- beaten
- booming
- bound
- bullheaded
- changeless
- chronic
- clamant
- clamorous
- committed
- consistent
- consonant
- constant
- continual
- continuing
- continuous
- correspondent
- crying
- decided
- decisive
- dedicated
- definite
- demanding
- determined
- devoted
- diligent
- dogged
- draining
- durable
- earnest
- echoic
- echoing
- enduring
- equable
- equal
- even
- evergreen
- exacting
- exigent
- exorbitant
- extortionate
- faithful
- fast
- firm
- fixed
- flat
- frequent
- frozen
- gluey
- glutinous
- grasping
- gummy
- habitual
- hackneyed
- hardy
- haunting
- homogeneous
- immobile
- immutable
- importunate
- inalterable
- incessant
- indefatigable
- indelible
- indomitable
- industrious
- inflexible
- insistent
- instant
- intact
- interminable
- invariable
- inveterate
- invincible
- inviolate
- lasting
- level
- long-lasting
- long-lived
- long-standing
- long-term
- loud
- loyal
- macrobiotic
- measured
- mechanical
- monolithic
- nagging
- obdurate
- obsessive
- obstinate
- ordered
- orderly
- patient
- perdurable
- perennial
- permanent
- perpetual
- persevering
- persisting
- pertinacious
- plodding
- preoccupied
- pressing
- purposeful
- quiescent
- rapt
- recurrent
- recurring
- reechoing
- regular
- relentless
- remaining
- repetitive
- resolute
- resolved
- resounding
- reverberant
- reverberating
- rigid
- robotlike
- routine
- rumbling
- sedulous
- serious
- sincere
- single-minded
- sleepless
- smooth
- solid
- sounding
- stable
- static
- stationary
- staunch
- steadfast
- steady
- stereotyped
- sticking
- sticky
- stubborn
- sustained
- systematic
- tacky
- taxing
- tenacious
- thundering
- tireless
- torpid
- tough
- trite
- unaltered
- unbroken
- unceasing
- unchangeable
- unchanged
- unchanging
- unchecked
- unconquerable
- undaunted
- undeveloped
- undeviating
- undifferentiated
- undiscouraged
- undiversified
- undying
- unending
- unfading
- unfailing
- unfaltering
- unflagging
- unflinching
- unforgettable
- uniform
- uninterrupted
- unrelenting
- unremitting
- unruffled
- unshakable
- unsleeping
- unswerving
- untiring
- unvaried
- unvarying
- unwavering
- unwearied
- unwearying
- urgent
- viscid
- vital
- well-worn
- wholehearted
