keeping nose the grindstone (verb) keep one's nose to the grindstone: work doggedly
Sinonime: borderline, debatable,
different, disputable, doubtable,
dubious,
equivocal, farfetched,
funny*,
irregular, not kosher,
open, open to doubt, open to question, out of line,
overt,
peculiar,
phony,
problematic,
queer,
questionable, reaching, rings untrue,
shady,
shaky*,
suspect,
too much*,
uncertain,
uncommon,
unsure,
unusual, won't wash
Antonime: believable, indubious,
palpable, undoubted, unquestionable