The noun 'excession'?

I’ve just been at a talk on financial models. The speaker constantly used the noun ‘excession’ to describe the situation where a fixed limit was exceeded. I’ve never heard it before. The normal usage here would be the noun ‘exceedence’.

Is this a cutting edge neologism? Or just an ignorant speaker?

Someone has been reading too much science fiction:

There’s an entry for ‘excession’ in the Oxford English Dictionary, defined as “a going out or forth.” The first date of occurrence is 1655. It comes from the same Latin as “exceed”, in the sense of passing a boundary.

It’s a real word, just one that hardly anyone ever uses.

It would be? I’ve never heard of that word. I’d use ‘excess’.

It’s commonly used in statistical modelling. ‘Exceedence’ is the act of exceeding a limit. ‘Excess’ is the amount by which the limit has been exceeded.