What is "outheroding"?

The meaning Scott intended is to outdo in absurdity (I came across that unusual definition in an online dictionary, but lost the reference - sorry).

All my dictionaries limit their definition to outdo in cruelty, if they even list the word at all. The proverbial saying is to out-Herod Herod - which isn't particularly common in the first place, but when it is used, that's nearly always the form.

In all Google NGram's vast corpus, outherod (or outHerod) appears on average less than once a year, and nearly all of those occur as outHerod Herod in the actual text (i.e. - explicitly repeating the full saying). NGrams doesn't support searching for out-herod, but presumably there would be more results for that if it did.

The expression appears in this quite old text of Shakespeare's Hamlet as it outHerod's Herod, but I couldn't say if that's how the Bard himself wrote it. However, I suspect he may have been the first to write it at all.

Note that out-(someone) (someone) is a fairly standard way of generating "one-off" expressions like this today. Google returns 130K hits for out-Bush Bush and 50K for out-Blair Blair, for example. That compares to 20K for the Herod version, just to put it in context.

In my opinion, out-Herod (irrespective of hyphenation or capitalisation) isn't really a 'word' at all. It's just a transient lexical element that no more deserves to be in the dictionary than out-Obama (which gets over 230K Google hits, by the way).

I'm no biblical scholar, but I don't think Herod has any particular reputation for extravagance or absurdity. As far as I know, extreme cruelty as exemplified by the Massacre of the Innocentswas his proverbial quality. So I think Scott's usage was grammatically, typographically and semantically perverse, to say the least.

"outheroding" is a present participle form of "outherod".

Here is the definition for "outherod".

to outdo in extravagance, violence, or excess: His cruelty out-Herods Herod.

outheroding [present participle form of outherod] means:

    "To surpass someone in cruelty or evil".

refers to the figure of biblical Herod, who allegedly had the innocent babies slaughtered. In popular medieval churchplays often presented by actors in an exaggerated way as pure evil. That is what Hamlet refers to when he talks to a troup of actors he asks to stage the murder of his father, meaning that to achieve the effect wished for (mirroring his horrible deed to his uncle) they have to act in a realistic way.