敦 (duì) is a bound form (b.f.) meaning 'honest, sincere' or 'stocky, sturdy', appearing in compounds such as 敦厚 (honest and sincere), 敦实 (stocky and strong). However, the standard modern pronunciation for this character is dūn (first tone); the duì reading listed here is rare and may be a data error. In practical use, you will almost always encounter it as dūn.