1Strange, odd, or peculiar — something that seems unusual or off.
彼の様子が最近ちょっと変だ。
His behavior has been a bit strange lately.
そんなことを言うなんて、変な人だ。
Saying something like that — what a strange person.
その映画は設定が変で、よく覚えている。
That movie's premise was odd; I remember it well.
2Unexpected or surprising; describes something out of the ordinary that catches one off guard.
変なタイミングで昔の同僚から連絡が来た。
An old coworker contacted me at an unexpected moment.
変な偶然だが、二人は同じ電車に乗り合わせた。
By a strange coincidence, the two of them happened to be on the same train.
3A literary noun usage meaning "change" or "alteration." In modern Japanese this sense is rarely used on its own — 変化 is used instead almost universally.
4An incident, disturbance, or disaster — a sudden, abnormal event (literary noun usage). In modern Japanese it survives mainly in historical incident names, such as 本能寺の変 (the Honnō-ji Incident).
本能寺の変は1582年に起きた歴史的な事件だ。
The Honnō-ji Incident was a historic event that occurred in 1582.
幕末には桜田門外の変をはじめ、多くの変が起こった。
In the late Edo period, many such incidents occurred, including the Sakuradamon Incident.
5In music notation, a prefix indicating "flat" (♭), used in key names (e.g., 変ロ短調).
この曲は変ロ短調で書かれている。
This piece is written in B-flat minor.