Please explain the bolded words below from this passage in "Compliments of the Season."i want to know the meaning of :- His hand was itching to...

In the part of the story that you quote for us, Fuzzy has
found the doll but does not know of its significance.  Black Riley does know that he
could get money for the doll.  This is the background to the passage that you have
given.

There are two parts of the passage that must be
explained.  First, the part about the Romans and the Sabine.  In Roman legends, there is
an episode in which Roman men supposedly went and took wives from a neighboring
community.  You can find more about this episode in the link below (the Rape of the
Sabine Women).  So what O. Henry is saying here is that Black Riley wants to take the
doll away by force.

Second, there is the phrase
"merry-andrew."  This is a phrase that is used to refer to a clown or a buffoon of some
sort.  So, by including this phrase, O. Henry is is showing that Black Riley looks down
on Fuzzy and thinks that he is some sort of an idiot.