mega menu

noun

mega menu

noun

1

Computing, Engineering, Graphical user interface, Mathematics, Natural sciences, Physical sciences, Sciences Internet A complex menu that may incorporate subheadings, images, and other content.

There has actually been a recent trend of several major e-commerce websites moving their top menu to the left, using fly-out mega menus instead.2012, Rich Page, Website Optimization: An Hour a Day:
They use mega menus carefully, with a mega footer only on the home page.2015, Andy Grogan, Accidental Encyclopedia, page 29:

2 more examples

However, mega menus can be difficult to implement so that they are usable with the keyboard and work on small devices.2016, Patrick J. Lynch, Sarah Horton, Web Style Guide, 4th Edition, page 229:
If you're unlucky, you have one of those clients who wants MEGA menus with a hierarchy of menus with many links.2016, Kelt Dockins, Design Patterns in PHP and Laravel, page 72:

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.