Gordian knot
baffle
bafflement
bewilderment
bother
confoundment
confusion
crux
difficulty
dilemma
discomposure
disconcert
disconcertedness
disconcertion
disconcertment
disturbance
doubt
embarrassment
enigma
fix
jam
knot
knotty point
mystery
node
nodus
nonplus
oxymoron
paradox
perplexity
perturbation
pickle
plight
pons asinorum
poser
pother
predicament
problem
puzzle
puzzlement
riddle
scrape
stew
teaser
unassuredness
uncertainty
upset
conundrum
cryptogram
disquietude
excellences
frailness
heirarchy
imbroglio
instrumantmarket
misgiving
muddle
mystification
nature
peccant
probings
reframing
squelching
underpin