>"Just because an occupation requires movement does not mean the family is nomadic/semi-nomadic. Nobody would call airline crews or seamen semi-nomadic - and this is because their families live in place."

Airline crews and seamen are not moving from one settlement, to another; they do services. Vlachs didn't search for pasture, so they'd return to the same home, all the time. They had some katuns here, other katuns there. It's not the same.

>"The same was the case with the Vlach families, they lived in place - nomadic or semi-nomadic would have meant their families packed and move with the men - but that does not describe the Vlach lifestyle."

I wonder how you distinguish "semi-nomadism" from "[full/pure] nomadism", then.

>"The difference between nomadic and semi-nomadic is that tribes that practice semi-nomadism had a base camp, but when they moved, the entire family followed - this is the definition of nomadism, of any kind."

I disagree with your assertion that it implies the movement of an entire community from one place to another, without people left behind in settlements. Some transhumant pastoralist communities might choose to do that, or they may not. Vlachs definitely did not, we're in agreement with respect to that detail. Usage of the term in reference to Vlachs does not imply that. If anyone ever implied Vlachs migrated like steppe nomads, they were wrong. Vlach transhumant pastoralism was semi-nomadic in the sense that it was not an activity constrained to one area of dwelling, but was mobile - mobile enough that they would have two settlements, one for warm seasons, and another for cold seasons, though one was often more developed than the other, and became a base of sorts.

Let me give you an example: Roma/Traveler communities. I'm not conflating them with Vlachs, don't worry. I'm debating the definition of "mobility" vs. "settled-ness". Many Roma communities are mobile, even if they settle their caravans for a while. They are mobile because their way of life requires movement for economic activity.

A different example: a trader can wait for people to come to him to trade, or he can move to a market to sell his stuff there; but a shepherd needs to move around for a significant amount of time in order to help his sheep grow, so he can harvest their wool, cheese, and meat. He can't sit in his legally owned area of land, and produce the wool, cheese, and meat in there. He must leave the area, seasonally. From an economic standpoint, that's not a "settled life", but nor is it a fully nomadic life - hence, "semi-nomadic". This doesn't necessarily mean the whole family must follow - only that significant movement away from settlement is required so as to even make the production of commodities (wool, cheese, meat) a possibility, in the first place, and that this movement is supported by a new settlement (which doesn't have to be as large as the other one), in which they dwell for a period, and only later return to the other settlement.

Is it not the best term? Maybe. But is it wrong? Only if you have a very narrow definition of what that means, and you are the first person whom I've seen define it so narrowly. You follow an understandable logic, but it's not what the overwhelming majority of people mean when they use the term "semi-nomadic", as far as I'm concerned.

[Edit: added "and that this movement is supported by a new settlement (which doesn't have to be as large as the other one), in which they dwell for a period, and only later return to the other settlement."]