When you automatically nod or say yes to agree to whatever the other person is saying, not necessarily because you agree with this person, but because you're not paying attention. Combo of "agree" and "reflex."
"When Megan started to tell me about the benefits of the vegan lifestyle, my agreeflex kicked in and I went to my happy place. She never even realized I didn't hear a word of it."
de CorneliusMaxter 25 Ianuarie 2009