keep one's nose to the grindstone (verb) keep one's nose to the grindstone: work doggedly
Sinonime: Greek to me,
abstract, clear as dishwater,
complex,
complicated,
deep, enigmatic,
esoteric,
heavy*,
hidden, incomprehensible,
intricate, involved, muddy, obscure, perplexing,
profound, puzzling,
recondite,
subtle, unfathomable,
vagueAntonime: clear,
concrete,
easy,
lucid,
obvious,
plain,
simple