Gilbert Arenas wasn't lying when he said he would make his sex tape accuser pay ... he just settled his lawsuit with her -- and claims SHE had to write HIM a check for lying.
As we previously reported, Janelle Reeves got a restraining order against Arenas after telling the court he had been harassing her and threatened to release a sex tape of her to her own minor son.
Arenas claimed the woman was making the whole thing up and sued her for defamation -- demanding $10 MILLION in damages -- insisting he lost his job at Yahoo Sports as a result of the allegations.
The case was dismissed earlier this month, according to court record -- and now Gilbert's attorney, David Bass, tells TMZ Sports ... it's all because Reeves folded like a cheap suit.
"[Reeves] resolved the dispute by paying Mr. Arenas an undisclosed amount for his damages and confirming that the restraining order action of June 2018 was meritless, filed with fabricated documents and, therefore, filed without cause."
Reeves released the following statement to us, saying ... "I am generally a reclusive person, a lover not a fighter. I can't help it. My naivety to a lot of things landed me in situations that are not what I thought they would be."
"I am a person of integrity, honor, and love. And I will continue to be that. I am working through it all and am so glad to have moved on past this never to associate with the individual involved again."
No word on how much Gilbert received -- but it's not like he needs the money ... Arenas made more than $160 MILLION in his NBA career.