1. a thin curved piece of metal or plastic sewn into the bottom of a bra cup to provide support and shape

1. having or containing an underwire for support

Examples

• The underwire in her bra was poking through the fabric.
• She prefers bras without underwire for comfort.
• The underwire provides extra support for larger cup sizes.
• An underwire bra gives a more defined silhouette.
• She switched to wireless bras after the underwire broke.
• The underwire should sit flat against your ribcage.
• Many sports bras don’t have underwire for better flexibility.