1. 威胁的;威吓的;危险的
If someone or something looks menacing, they give you a feeling that they are likely to cause you harm or put you in danger.

1. threatening or foreshadowing evil or tragic developments

e.g. a baleful look
forbidding thunderclouds
his tone became menacing
ominous rumblings of discontent
sinister storm clouds
a sinister smile
his threatening behavior
ugly black clouds
the situation became ugly

Synonym: balefulforbiddingminaciousminatoryominoussinisterthreatening