THose who know Greek...have a question?

cant really help you :-) but just wanted to recommend a free greek course and much info on grammar etc, on itunes store there is a video series download from Concordia seminary if anyone is interested, goes through the basics and some more, worth looking into for those who might wanna broaden their greek skills

"what does the "X" mean "

What I know about Greek you could write on a pinhead. It seems to me however, given the context that you quoted, that the "X" simply means "times". It could be rewritten "exceedingly, many times great, grief, or harm, or.....' speaking of potential great amounts of whatever.
My understanding about masculine and feminine forms is that they are not to be too excited about especially as they refer to neuter objects. Often a form is given or ascribed to a noun or adjective but it need not necessarily denote gender but simply that this particular object is described often, though not always, in this gender form. It would be similar to the way in which when using the English language we often refer to storms or inanimate objects in a gender form, "she was quite a storm", but realizing that it is not of any gender.
Perhaps someone of greater knowledge could explain better. I am only surmising.

If you look at a dictionary's explanations and notes (usually at the beginning), you'll find that in Strong's, it denotes a rendering of the word in the Authorized Version that is the result of an idiom particular to the original language. So the words that follow the 'X' are idiomatic translations.

The "feminine" form of a word is simply a syntactical construct. In the case of adjectives and many nouns, if a word has a specific gender, it does not mean that the object characterizes a certain sexual gender. Adjectives and verbs usually must agree in number and gender with their subject.

I would suggest that for the most part, those who do not have a basic knowledge of Greek syntax (sentence/phrase construction) should have no concern about the gender of various words (same goes for Hebrew).

I would give a word of caution to those who would desire to build any theological case upon a shaky foundation of biblical languages. There is a great possibility for much harm to both the text and theology when an "exegete" lacks adequate understanding of vocabulary, grammar, and syntax.

For all who are desirous however, I would suggest proper training under the instruction and supervision of those who have a thorough grasp of the language.

Grace and peace,
Brad.