deadly
adj.adj. likely to cause death or very dangerous. It can also describe something that is extremely boring or something done with great skill and accuracy.
adj. capable of causing death; fatal. Also used to describe extreme dullness or, in a more positive sense, high levels of precision and effectiveness.
The snake has a deadly bite.
The soldiers faced a deadly combination of freezing temperatures and limited food supplies.
While the protagonist's aim was deadly, his social skills were famously lacking, making the long dinner parties feel like a different kind of torture.
From Middle English dedly, dedlych, dedlich, from Old English dēadlīċ (adjective), from Proto-West Germanic dauþalīk, from Proto-Germanic dauþalīkaz (“deadly”, literally “deathly”). By surface analysis, dead + -ly. Cognate with Saterland Frisian dodelk (“deadly”), West Frisian deadlik (“deadly”), Dutch dodelijk (“deadly”), German tödlich (“deadly”), Swedish dödlig (“deadly, fatal, mortal”), Icelandic dauðlegur (“mortal”). The adverb is from Middle English dedliche, from Old English dēadlīċe (adverb), from the adjective.
Typically used before a noun to modify it, but can also follow a linking verb like 'is' or 'became'.
He was deathly injuredHe was deadly injuredLearners often confuse 'deadly' (likely to cause death) with 'deathly' (resembling death, like being 'deathly pale').