gravid, grueling, laboured, dense, cloudy, ponderous, lumbering, punishing, inauspicious, big, impending, expectant, minacious, cloggy, imminent, arduous, leaden, operose, heavy, labored, impenetrable, sound, backbreaking, glum, foresight, hard, grim, sullen, saturnine, fleshy, minatory, enceinte, large, great, near, toilsome, with child, clayey, dark, dour, lowering, profound, sonorous, moody, weighed down, black, weighty, baleful, ugly, overweight, gruelling, grievous, morose, laborious, sinister, baneful, wakeless, grave, sour, intemperate, ill, forbidding, glowering
dangerous (part of speech: adjective)
endangering (part of speech: verb)
alarming (part of speech: verb)
frightening (part of speech: verb)
warning (part of speech: verb)
threatening (part of speech: verb)
- And they searched without result, until it was black night and the threatening storm at last fell. - "The Matador of the Five Towns and Other Stories", Arnold Bennett.
- Owen made no attempt to reply, and the manner of the crowd became every moment more threatening. - "The Ragged Trousered Philanthropists", Robert Tressell.
- " Tell us the truth or we'll tie you to that tree and shoot you," said one of them in a threatening tone. - "The Social Cancer A Complete English Version of Noli Me Tangere", JosÃ© Rizal.