1‘the bottle was made of opaque glass so that the contents could not be seen’
non-transparent, cloudy, filmy, blurred, smeared, hazy, misty, dirty, dingy, muddy, muddied, grimy, smeary
transparent, translucent, clear
2‘federalism renders the decision-making process opaque and bureaucratic’
obscure, unclear, dense, uncertain, indeterminate, mysterious, puzzling, perplexing, baffling, mystifying, confusing, enigmatic, inexplicable, unexplained, concealed, hidden, unfathomable, incomprehensible, impenetrable, vague, ambiguous, Delphic, indefinite, indistinct, hazy, foggy, nebulous, equivocal, doubtful, dubious, oblique, elliptical, oracular, cryptic, deep, abstruse, recondite, arcane, esoteric, recherché
informal as clear as mud
We take a look at several popular, though confusing, punctuation marks.