[CTcard]

Full Definition of MEDIOCRE

:  of moderate or low quality, value, ability, or performance :  ordinary, so-so

Related to MEDIOCRE
Synonyms
common, fair, indifferent, medium, middling, ordinary, passable, run-of-the-mill, run-of-the-mine (or run-of-mine), second-class, second-rate, so-so
Antonyms
excellent, fine, first-class, first-rate, good, high-grade, superior, top-notch

Sorry, but mediocre doesn't mean average. It means barely passable.

No need to apologize.
In the case at hand, it appears to have been used to mean not-passable at all.

The definition you linked indicates average with a negative connotation - matching the definition I came up with off the top of my head. 

There are many dictionaries with many definitions of mediocre which run from "average with a negative connotation" to the more common use in sports-related discussions that is much closer to "bad".

Indeed, I could have been more precise in my framing of the issue. I should have edited my preface to be something closer to: The problem with the term "mediocre" is that it has a range of meaning from bad to average, and one is never quite sure where along the spectrum the writer is aiming.

[CTcard]

Full Definition of MEDIOCRE

:  of moderate or low quality, value, ability, or performance :  ordinary, so-so

Related to MEDIOCRE
Synonyms
common, fair, indifferent, medium, middling, ordinary, passable, run-of-the-mill, run-of-the-mine (or run-of-mine), second-class, second-rate, so-so
Antonyms
excellent, fine, first-class, first-rate, good, high-grade, superior, top-notch

Sorry, but mediocre doesn't mean average. It means barely passable.

No need to apologize.
In the case at hand, it appears to have been used to mean not-passable at all.

The definition you linked indicates average with a negative connotation - matching the definition I came up with off the top of my head. 

There are many dictionaries with many definitions of mediocre which run from "average with a negative connotation" to the more common use in sports-related discussions that is much closer to "bad".

Indeed, I could have been more precise in my framing of the issue. I should have edited my preface to be something closer to: The problem with the term "mediocre" is that it has a range of meaning from bad to average, and one is never quite sure where along the spectrum the writer is aiming.