She smiled indefinably, leaving everyone around her curious.

The indefinable in a painting is often what keeps viewers returning to it.

She felt an indefinable sense of sadness as she walked through her childhood home.

The indefinableness of her smile made him wonder what she was thinking.

The indefinability of her feelings puzzled everyone at the reunion.

The committee's repeated references to indefinity in the report made it difficult to decide on a clear course of action.

The report's numerous indefinities made it difficult to form a clear policy.

Philosophers often debate the indefinabilities that arise when language meets paradox.

Philosophers often debate whether certain concepts count as indefinables, resisting any neat definition.