You explained what I felt but couldn't find written support/reference.
At first I considered the fact that 'mean' is a Stative verb, but similar
verbs such as 'know' can be used in the present perfect. Would you compare
'mean' to 'seem'? It doesn't sound right: 'It has seemed possible lately.'
I have found in teaching EFL that these types of situations are most
difficult to get across to non-native speakers. These are somehow "a feeling or
an inner grammar of a sort" that guides us not to use a certain structure with
specific verbs.
Dalia--
I believe that your problem with the verb 'mean' has to do with the
duration of the event that the verb describes and with our notion of time as
designated by present perfect tense.
We tend to use present perfect tense to describe events that go on for a
period of time, but that generally have the possibility of ending (and of
beginning, for that matter)
--I have worked at this university for one month.
--I have lived in Maryland for 10 years.
But the verb 'mean' is odd in this way because we tend to think of meaning
as a more or less lasting state, not a temporary state (though that is
possible) and not an action or event that can begin and end (though that is
also possible). These examples demonstrate that:
--The word 'bad' means 'good' in the lingo of the 80s. (state)
--*The word 'bad' has meant 'good' in the lingo of the 80s
--That is not what I meant. (past act)
--?That is not what I have meant.
So here is an example that clarifies an endpoint of the event, and the
present perfect seems to work:
--Until recently, the word 'bad' has meant 'something good.' Now,
however, the word 'bad' means 'something terrible.'
I hope that this simple explanation helps!
Linda