Tough nut to crack

Synonyms for tough nut to crack
noun mystery

conundrum
puzzle
riddle
mystification
perplexity
stickler
question
secret

cliffhanger
twister
puzzlement
cryptogram
parable
crux
puzzler
knot

why
bewilderment
problem
stumper
sticker
grabber
teaser
sphinx

Gordian knot
mind-boggler
mind-twister
question mark
sixty-four dollar question

Synonyms
noun puzzle, secret

riddle
conundrum
subtlety
question
enigma
secrecy
problem
mystification
perplexity
stickler

cliffhanger
twister
occult
puzzlement
cryptogram
crux
difficulty
poser
why
charade

oracle
sixty-four-thousand-dollar question
thriller
stumper
abstruseness
grabber
whodunit
chiller
teaser
inscrutability

sphinx
rune
rebus
brainteaser
braintwister
closed book
inscrutableness
mindboggler

Antonyms

known

understanding

Synonyms
adj pigheaded, stubborn

adamant
callous
dogged
firm
fixed
hard
hard-boiled
hard-nosed
harsh
heartless
immovable

implacable
inexorable
inflexible
iron
mean
mulish
obstinate
perverse
relentless
rigid
thick-skinned

tough
unbending
uncompromising
uncooperative
unemotional
unfeeling
unrelenting
unshakable
unsympathetic
unyielding
indurate

uncompassionate
cold fish
bullhead
hanging tough
hard-hearted
set in stone
stiff-necked
unimpressible

Antonyms

submissive
susceptible

amenable
gentle

yielding

Synonyms
noun brain-teaser

mystery
dilemma
conundrum
puzzle
quandary
complexity
enigma
strait
mystification
perplexity

plight
complication
stickler
question
doubt
maze
twister
puzzlement
cryptogram
labyrinth

confusion
embarrassment
entanglement
poser
distraction
predicament
bewilderment
charade
intricacy
problem

teaser
stumper
rebus
brain-twister
closed book
knotty question
mind-boggler
sixty-four dollar question
tough proposition

Antonyms

simplicity
solution

good fortune
confidence

Synonyms
adj stiff, strict, severe

uncompromising
stringent
austere
harsh
solid
hard-line
definite
unyielding
inflexible
intransigent
stern

rigorous
adamant
fixed
exact
bullheaded
changeless
determined
firm
hard
inelastic
inexorable

invariable
obdurate
set
single-minded
static
strait-laced
unalterable
unbending
unbreakable
unchanging
unmoving

unrelenting
adamantine
incompliant
chiseled
dead set
locked in
set in stone
undeviating
unpermissive

Antonyms

willing
inexact
tolerant
unreliable
indefinite
irresolute
lenient

bending
limber
pliable
flexible
gentle
mild
easy

soft
broken
imprecise
unfixed
yielding
pliant

Synonyms
noun mystery

puzzlement
riddle
conundrum
puzzle
mystification
stickler
question
cliffhanger
charade
subtlety

occult
cryptogram
crux
puzzler
enigma
secrecy
poser
why
twister
difficulty

oracle
problem
sixty-four-thousand-dollar question
stumper
rebus
abstruseness
grabber
whodunit
chiller
teaser

thriller
inscrutability
sphinx
rune
brainteaser
braintwister
closed book
inscrutableness
mindboggler

Antonyms

harmony

Synonyms
noun mystery

riddle
conundrum
puzzle
mystification
perplexity
stickler
question
cliffhanger
twister
subtlety

occult
puzzlement
cryptogram
crux
difficulty
enigma
secrecy
poser
why
charade

oracle
problem
sixty-four-thousand-dollar question
stumper
rebus
abstruseness
grabber
whodunit
chiller
teaser

thriller
inscrutability
sphinx
rune
brainteaser
braintwister
closed book
inscrutableness
mindboggler

Antonyms

harmony