TL;DR: Is it possible to define hierarchy, as a useful term for communication and association between anarchists? If so, what are some of those definitions?

There are many different strains of anarchism, and specially since anarchists mostly believe in decentralization, I feel like many of our efforts go diluted for lack of collective organization. Sure, there are big anarchist collectives doing work out there, but I have the sensation that most youth or influential people who identify themselves with anarchist causes get lost in the plot simply for lack of a bigger movement. For most of the modes of anarchism there is one big bad evil guy, commonly named "hierarchy"; although writers and academics define those terms in their publications, I can't help but notice, at least in the forums I've been around, your average anarchists could be talking about two completely different concepts of hierarchy or oppression. Maybe if we had agreed upon definitions to those hot topics it would be easier to associate. Is that even possible? That we all agree on the same meaning for a word? Do we call Chomsky to solve this linguistical issue?

Or am I completely wrong in my questionings?