Definition: someone who shows excessive sympathy and attention toward another person, typically someone who does not reciprocate the same feelings, in order to win their affection
This is known as Internet slang, but apparently it’s been around since the early 1900s as a shortened form of “simpleton.”
The Urban Dictionary does not disappoint:
[…] it means a guy that is overly desperate for women, especially if she is a bad person, or has expressed her disinterest in him whom which he continues to obsess over
[…] It is when a male is overly submissive to a female and gains nothing from it. So overly submissive that other guys cringe and feel ashamed when seeing them.
[…] Simps usually cry by themselves, listen to sad music that relates to their situation, and they vent a lot. On social media they sometimes follow Wholesome memepages and send them to their friends and relate them to their current status with the female. Simps often don’t cry in public they just look very sad and it’s pretty obvious.
“Simp” has high usage among the male rights, incel, red pill, and MGTOW communities.
Why I Looked It Up
I said something nice to my wife in the car, and both my teenage daughters called me a “simp” from the backseat.