What is the meaning for an Arabic word henna?

Henna is the name of a flowering plant, Lawsonia inermis, also known as the henna tree, mignonette tree, and Egyptian privet. The name "henna" comes from the Arabic word الحِنَّاء ‎(al-ḥinnāʾ). Henna has been used since ancient times to dye skin, hair, and nails. The leaves of the henna plant are dried and ground into a powder, which is then mixed with water to form a paste. The paste is applied to the skin, hair, or nails, and left to dry. The henna will stain the skin, hair, or nails a reddish-brown color.