treacherously
/ˈtretʃərəsli/ (bre, ipa) · /ˈtretʃərəsli/ (ame, ipa)
treacherously — adverb
1. Describing weather, roads, or terrain as deceptively unsafe — appearing harmless
Describing weather, roads, or terrain as deceptively unsafe — appearing harmless while hiding serious risk to anyone who uses them.
The mountain road was treacherously icy, so Lara drove at walking speed.
modifies adjective: treacherously icy
The currents near the shore can be treacherously strong even for experienced swimmers.
modifies adjective: treacherously strong
Trang warned the hikers that the trail became treacherously steep after the first bridge.
Cole lost his footing on the treacherously slippery rocks and twisted his ankle.
- dangerously
more general; does not carry the 'deceptively unsafe' nuance
- precariously
focuses on instability rather than hidden danger
用法筆記
Commonly modifies adjectives describing the condition of terrain, roads, or water (icy, steep, strong, slippery). The sense highlights that the danger is not obvious at first glance.
2. Acting against a person who has placed their trust in you, by secretly harming,
Acting against a person who has placed their trust in you, by secretly harming, cheating, or working against their interests.
Tamar discovered that her colleague had acted treacherously by leaking private emails to the manager.
collocation: act treacherously
The general accused the officer of behaving treacherously by passing information to the enemy.
collocation: behave treacherously
Roya felt that Yasmin had spoken treacherously about her behind her back.
The village elder had acted treacherously by telling the raiders where the food was hidden.
- deceitfully
emphasises lying rather than breaking trust in general
- disloyally
more literal; focuses on failing to stay loyal
- faithlessly
very formal and literary
用法筆記
Formal register; more common in written narratives (news, historical accounts, fiction) than in everyday conversation about personal disputes.