rigorous (adj.)
- abstruse
- accurate
- acid
- acidulous
- acrid
- acrimonious
- acute
- adamant
- adamantine
- adverse
- algid
- antagonistic
- arctic
- arduous
- ascetic
- astringent
- attentive
- biting
- bitter
- bleak
- boreal
- brisk
- brumal
- brutal
- burdensome
- cast-iron
- caustic
- close
- cold
- complex
- conflicting
- conscientious
- constant
- contrary
- correct
- counter
- counteractive
- crisp
- critical
- cutting
- delicate
- demanding
- detailed
- detrimental
- difficult
- direct
- double-edged
- dour
- draconian
- drastic
- edged
- even
- exact
- exacting
- excessive
- exigent
- exorbitant
- express
- exquisite
- extravagant
- extreme
- faithful
- fierce
- fine
- finical
- finicky
- firm
- flinty
- formidable
- frigid
- fundamentalist
- furious
- fussy
- gelid
- glacial
- great
- grim
- hairy
- hard
- hard-core
- hard-fought
- harmful
- harsh
- hibernal
- hidebound
- hiemal
- hostile
- ice-cold
- icelike
- icy
- immoderate
- immovable
- immutable
- implacable
- incisive
- inclement
- inelastic
- inerrable
- inerrant
- inexorable
- infallible
- inflexible
- inimical
- intemperate
- intense
- intransigent
- intricate
- iron
- ironclad
- irreconcilable
- keen
- knotted
- knotty
- laborious
- mathematical
- mean
- meticulous
- microscopic
- minute
- miserable
- mordacious
- mordant
- muscle-bound
- narrow
- nice
- nipping
- nippy
- numbing
- obdurate
- obstinate
- onerous
- operose
- opposed
- opposing
- opposite
- oppressive
- orthodox
- outrageous
- particular
- penetrating
- piercing
- pinching
- poignant
- precise
- procrustean
- proper
- punctilious
- punctual
- puritanic
- raw
- refined
- relentless
- religious
- right
- rigid
- rock-ribbed
- rockbound
- rough
- rugged
- scathing
- scientific
- scrupulous
- severe
- sharp
- sinister
- sleety
- slushy
- snappy
- spiny
- splitting
- square
- stabbing
- steely
- steep
- stern
- stiff
- stinging
- stone-cold
- straightlaced
- straitlaced
- strenuous
- stressful
- strict
- strident
- stringent
- stubborn
- subtle
- tart
- thorny
- ticklish
- toilsome
- tough
- trenchant
- tricky
- troublesome
- troublous
- trying
- unaffected
- unalterable
- unbending
- unchangeable
- uncompromising
- unconscionable
- undeviating
- unerring
- unfavorable
- unmoved
- unrelenting
- untoward
- unyielding
- uphill
- vehement
- venomous
- violent
- virulent
- vitriolic
- wicked
- wintery
- wintry
- wretched
Rigorous law is often rigorous injustice.
