1.
to be overcome with emotion; to be too moved to speak
Being so filled with joy, gratitude, sadness, or nostalgia that one can hardly speak; literally 'the chest is full.' The emotion is marked with で: 感謝の気持ちで胸がいっぱいです, a fixture of speeches and thank-you messages.
Related Words
Related:
胸 (chest)
Related:
胸が痛む (to feel heartache)
Compare:
感動する (to be moved)
Compare:
胸が熱くなる (to feel a surge of emotion)