al·the·a also al·thae·a (?l-th???)n.1. See rose of Sharon.2. See hollyhock.[Latin, mallows, from Greek althaia, from althainein, to heal; see al- in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.althaea (æl??i??) or althean1. (Plants) any Eurasian plant of the malvaceous genus Althaea, such as the hollyhock, having tall spikes of showy white, yellow, or red flowers2. (Plants) another name for rose of Sharon2[C17: from Latin althaea, from Greek althaia marsh mallow (literally: healing plant), from Greek althein to heal]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014