unrelenting (adj.)
- adamant
- adamantine
- assiduous
- cast-iron
- constant
- continuing
- diligent
- dogged
- dour
- endless
- enduring
- extended
- faithful
- firm
- flinty
- fundamentalist
- grim
- hard
- hard-core
- hidebound
- immovable
- immutable
- implacable
- inalterable
- indefatigable
- indomitable
- industrious
- inelastic
- inexorable
- inflexible
- insistent
- intransigent
- invincible
- iron
- ironclad
- irreconcilable
- lasting
- lengthy
- long
- long-winded
- loyal
- merciless
- mortal
- muscle-bound
- obdurate
- obstinate
- orthodox
- padded
- patient
- permanent
- persevering
- persistent
- persisting
- pertinacious
- plodding
- preoccupied
- procrustean
- prolix
- protracted
- puritanic
- rapt
- relentless
- resolute
- rigid
- rigorous
- rock-ribbed
- rockbound
- ruthless
- sedulous
- single-minded
- sleepless
- stable
- steadfast
- steady
- steely
- stern
- stiff
- straightlaced
- straitlaced
- stubborn
- talkative
- tenacious
- tireless
- unaffected
- unalterable
- unappeasable
- unbending
- unchangeable
- uncompromising
- unconquerable
- undaunted
- undiscouraged
- unfailing
- unfaltering
- unflagging
- unflinching
- uninterrupted
- unmoved
- unremitting
- unsleeping
- unswerving
- untiring
- unwavering
- unwearied
- unwearying
- unyielding
- verbose
- windy
- wordy
Forever, Fortune, wilt thou prove
An unrelenting foe to love;
And when we meet a mutual heart,
Come in between and bid us part?
Arms and the man I sing, who, forced by fate
And haughty Juno's unrelenting hate.
