1. Indicating coincidence of high tides or low tides.
2. Of or relating to a line that passes through each location on a coastal map where tides occur at the same time of day.
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.
(Navigation) (of a line on a tidal chart) joining points at which high tide occurs simultaneously
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
1. pertaining to a coincidence of tides.
2. (on a chart or map) indicating a line connecting points at which high tide occurs at the same time.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.