warning/'wɔːnɪŋ $ 'wɔːr-/

n. sth that tells you that a bad or dangerous thing is likely to happen

n. [C; U] 警告；警报；先兆：[warning of sth] The weather report gave a warning of more snow. 天气预报发出了还要下雪的警报。

◇The dog attacked him without (any) warning. 那条狗毫无先兆地攻击了他。

构词warn + -ing