1. A man who behaves in an overly familiar way and is always replying to the social media messages of a woman he doesn't know or is barely acquainted with.

2. An annoying man who replies to social media messages, in general - whether this annoyance is due to a perceived know-it-all attitude, excessive familiarity, banal arguments that the annoyed user doesn't feel compelled to reply to again and again, or violation of some imagined pecking order.
Mental health improves 120% when reply guys are blocked or muted
by Esther Lolstein December 20, 2018
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A guy that replies.
Oh look that reply guy is replying to all the comments.
by Nezahualcoyotl December 22, 2018
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The greatest man on earth that is employed at Applebee's. He talks to fans of Applebee's on the facebook page.
Your lord and savior.
Have you accepted Applebee's Reply Guy as your lord and savior?
by LCFlygon July 27, 2012
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