Dave at Balashon has an interesting post about bidur, and the idea that there is a class of words that start with bd, and all of which mean "single, separate."
I was having somewhat related thoughts about a class of words that start with pr and mean "scattered, separate." I encountered this while learning through beitza where the objection is made that an egg laid from a hen which stands to be eaten is `uchla de`iphrath hu`, food which merely splits and separates from itself. The root is prt but Rashi translates it as prd.
I thought it might just be replacing the voiceless dental (t) for the voiced dental (d), but then I thought it might be standard Aramaic switching of certain shin for tav, thus coming from pr$. Jastrow lists this as a separate word and root.
Thus, we have:
prg - a separation (see pargod, separating curtain, and related Greek word)
prd - to separate
prz - scatter
prk - also to separate
prs - a piece
pr' - to peel off
prtz - a break in something
prq - a section
prr - a piece, a crumb, to crumble
prt - as above, to separate
There are also a series of these words that mean to bloom (e.g. pry, prhh).