Long, straight, and limp: lank and floppy hair. (adjective)
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 "lank" in a sentence
"And a smile played round my lips as I recalled his lank yellow hair (often standing on end), his sloping shoulders and his female hands -- a strange appearance which a certain vivacity of mind sometimes rendered engaging."
"Sunburnt and tall and kind of lank, but good-lookin '."
"Mr Barker suggested if they were going to "knife the Rubbish from Rio" then Mr Sono would be the perfect person to do it as he had "lank" experience of getting rid of Bafana coaches just before World Cups."