1.
suspicious, shady
Describes a person or thing that seems untrustworthy or potentially dangerous.
怪しい人がいる。
There's a suspicious person.
あの男の態度が怪しい。
That man's behavior is suspicious.
夜道で怪しい物音が聞こえた。
I heard a suspicious sound on the dark street at night.
2.
dubious, uncertain, unreliable
Describes something of questionable quality, accuracy, or likelihood.
天気が怪しい。
The weather looks iffy.
その話は怪しいと思う。
I think that story is dubious.
彼の日本語は怪しいけど、一生懸命話している。
His Japanese is shaky, but he's trying hard to speak.
FORMS: 怪しく (adverbial), 怪しさ (noun form).
Sense 1 covers people, behavior, and situations that arouse suspicion. Sense 2 covers things that are unreliable or of questionable quality — often used for weather, skills, or claims.
COMMON COLLOCATIONS:
- 怪しい人 — suspicious person
- 怪しい動き — suspicious movement
- 怪しい雲行き — ominous clouds; uncertain outlook
- 日本語が怪しい — one's Japanese is shaky
SIMILAR WORDS: 疑わしい focuses on doubt or disbelief, while 怪しい carries a nuance of something being creepy, off, or unreliable.