quickstart@qs10:~/websites/arbx.dev/sites/all/modules$ drush dl metatags
Project metatags (7.x-1.0-alpha1) downloaded to /home/quickstart/websites/arbx.dev/sites/all/modules/metatags. [success]
Project metatags contains 3 modules: metatag_opengraph, metatag_ui, metatag.
If people accidentally does drush dl metatags instead of drush dl metatag. It still will download. Please close down this trap; I personally spent 4 hours diagnosing the bugs introduced by having 2 of the same modules. metatag and metatags, and i would rather not have anyone go through this trap again.