ほころhokoroびるbiru
1.

To become slightly undone or loosened, often referring to a stitched seam or connection that has started to give way, creating a gap or opening.

2.

To begin to blossom or unfurl, particularly used in the context of flowers or buds that are starting to bloom.

3.

To display a gentle expression of joy or warmth, as in the softening of one's facial features or the emergence of a smile.

4.

To reveal emotions, secrets, or underlying feelings that can no longer be contained, allowing them to surface unexpectedly.

Example:

彼女のドレスのへりはほころびていた。