1.
definite, certain, clear
Something that is clearly known or established. Most commonly used in the negative form 定かではない to express uncertainty.
記憶が定かではない。
My memory is not clear.
原因は定かではないが、調査が進んでいる。
The cause is uncertain, but the investigation is progressing.
その伝説が事実かどうかは定かではないが、地元では広く信じられている。
Whether the legend is true is not certain, but it is widely believed locally.
定か is a na-adjective most commonly encountered in the negative form 定かではない or 定かでない, meaning "uncertain" or "not clear."
FORMS:
- Negative: 定かではない / 定かでない
- Modifier: 定かな情報 (definite information)
- Adverbial: 定かに (definitely) — rare
COMMON COLLOCATIONS:
- 記憶が定かではない (memory is unclear)
- 原因は定かではない (cause is uncertain)
- 真偽は定かではない (truth is uncertain)
USAGE:
The affirmative form (定かな, 定かだ) exists but is uncommon in modern Japanese. This word appears predominantly in negative constructions and in somewhat formal or written contexts.