Definition

An involuntary state of partial sexual arousal triggered in completely inappropriate situations where there's zero chance of acting on it, but your body optimistically disagrees with your brain.

Example Usage

I got a limp-on during that work presentation and had to sit down for another twenty minutes—thanks a lot, brain.

Source: Urban Dictionary (https://www.urbandictionary.com/define.php?term=limp-on&defid=2529116)