The ash tree Fraxinus quadrangulata, which is chiefly native to the Midwestern United States, and of which the inner bark has been used as a blue dye.
Late 18th century.
英汉双解词典包含464360条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。