A simp (n.) is someone who simps (intr. v.)
to simp / simping (v.)
This can be any act that benefits its recipient, with or without the
expectation of receiving something in return.
note: that the word "simp" can be used as derogatory or as non-derogatory. Usually, the derogatory use of the word "simp" implies that the person who is "simping", is doing so disingenuously with the goal of receiving something which the recipient would
otherwise not agree to give to them; concealing their true intension in-order to subvert the recipient's awareness of the true goal.
The most common example of "simp" being used as a
derogatory term is when a male "simps" to a female in order to gain leverage to pressure them into giving romantic or explicit favours.