A cassock, especially one that buttons up and down the front.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "soutane" in a sentence
"The priest hurries past on his way to say mass, the soutane flying superhero-style."
"Watts can provide you with a classical soutane - piped fuchsia edges an optional extra - but it's the glorious copes and chasubles that catch the eye."
"Navin Patel can go one better, having donned his surplus and soutane to line up for one such team."