I was fired because of an altercation with an employee. She had been insinuating laziness, by speaking the word "lazy" outloud indirectly (but within ear shot)weeks prior to my altercation with her. I am on an accepted Workman's Compensation claim (by the company insurance). I was on temporary work duty release profile with my job at the time. My question is: Is this work place harrassment? I do not have any witnesses to the fact that this employee was calling me lazy but I can state days of when she did. I also find that it is curious that I was fired during my Workman Comp claim
and before retraining began.

Is this work place harrassment? It's not illegal harassment if that's what you're asking.

I also find that it is curious that I was fired during my Workman Comp claim
and before retraining began. Except for the fact that you "got into an altercation" with this coworker.

In this context of being called lazy, prior harassments of being called lazy? Not harassment?

No, not harrassment. Illegal harrassment has a legal definition, and being called lazy does not even come close. Uncomfortable, maybe. Improper, probably. Illegal, no.