insistent (adj.)

• acute
• assertive
• assiduous
• burning
• clamant
• clamorous
• coaxing
• compelling
• constant
• continuing
• critical
• crucial
• crying
• demanding
• determined
• diligent
• dire
• dogged
• draining
• emphatic
• enduring
• exacting
• exigent
• exorbitant
• extortionate
• faithful
• firm
• forceful
• grasping
• high-pressure
• immutable
• imperative
• imperious
• importunate
• inalterable
• indefatigable
• indomitable
• industrious
• inexorable
• instant
• invincible
• lasting
• loud
• loyal
• nagging
• obstinate
• obtrusive
• patient
• permanent
• persevering
• persistent
• persisting
• pertinacious
• pestering
• pivotal
• plodding
• preoccupied
• pressing
• rapt
• relentless
• resolute
• resounding
• sedulous
• single-minded
• sleepless
• stable
• steadfast
• steady
• stubborn
• taxing
• teasing
• tenacious
• tireless
• uncompromising
• unconquerable
• undaunted
• undiscouraged
• unfailing
• unfaltering
• unflagging
• unflinching
• uninterrupted
• unrelenting
• unremitting
• unsleeping
• unswerving
• untiring
• unwavering
• unwearied
• unwearying
• unyielding
• urgent