どこ何処dokokaどっ何処doka
1.

A term used to refer to an unspecified or vague location, often indicating that the exact place is unknown or cannot be identified clearly.

2.

Used to express a sense of imprecision regarding a place or aspect, suggesting familiarity without specificity, such as a recognition of similarity or a general feeling that something is amiss.

3.

A more casual variant of expressing the concept of an uncertain location, often conveying a relaxed or informal tone in conversation.

Example:

財布をどこかこの辺に落としたんだ。