Mactastic......your title question ...

"What does disassociate mean?"

here in New York (the one in the USA as opposed to other locations) ...

disassociate means to detach from association

you make a conscious and willful choice to quit, leave, no longer be a part of something.....

examples.... I disassociated myself from a family dinner with my sibling, I disassociated myself from the company picnic....meaning I chose to not attend a family dinner at a siblings home and I chose to leave a company picnic early.

dissociation .....on the other hand means to feel numb, feel spacey, feel foggy minded, ...its a cover all word that covers many different symptoms.

some locations though do use the two terms ....disassociate and dissociate interchangably which can be a bit confusing for those of us like here where I live and work that do use the two terms as being two different definitions.

I usually as which term the person is posting about and give the definitions that are used here so the poster has something to go by in clarifying their post for me. that way I know which they are asking about.