And "order" doesn't fully capture it either, because the concept it gestures at can be more accurately described as "hierarchy" - as Kirk puts it, "a conviction that society requires orders and classes that emphasize "natural" distinctions".
In other words, everyone has a proper place in society, with some above and others below, and any attempts to remove that hierarchy are moral wrongs which require the transgressors to be put back in their place.
You can see how that core belief is intrinsically dangerous, and how nearly every controversial conservative belief about social classes falls out of it.
(It's also worth noting that this explains why conservatism's earliest champions were supporters of the aristocracy, and also why conservatism is more beloved by the old-money wealthy than move-fast-and-break-things new-money tech.)