undecipherable

adj

1. illegible, unreadable, indecipherable; unclear, Inf. clear as mud, indistinct, indistinguishable, undistinguishable, unrecognizable; blotted, blurred, smudged; (all of writing) cramped, squeezed, squeezed together, pinched; run-on, run together, strung together; deleted, erased, effaced, eradicated, wiped or rubbed out, blotted out

2. hieroglyphic, hieroglyphical, cryptographic, cryp-tographical, Obs. steganographic.

3. secret, hidden, concealed, veiled, cryptic, perdu; impenetrable, incomprehensible, uncomprehensible, unfathomable, inscrutable, unknowable, incognizable, incognoscible; abstruse, recondite, esoteric, abstract, heavy, Inf. heavy-duty.

4. difficult, hard, Inf. tough; complex, complicated, perplexed, Inf. tricky; intricate, involved, tangled, knotty, crabbed; obscure, dim, dark, vague, nebulous, Rare. imperspicuous; puzzling, baffling, enigmatic, enigmatical; mysterious, arcane, inexplicable, unex-plainable, insolvable, insoluble, unaccountable, inextricable.