[OT] Next word in this sequence of words ending with 'ty'

[Justin Johansson]

Lars T. Kyllingstad wrote:
>> Plurality, Singularity, ..
> 
> 
> BTW, is "singularity" ever used to describe one-ness?  (I know "singular" 
> is, but I'm not so sure about the "-ty"-form".)  In all contexts I have 
> encountered it, it means infinite-ness.  I'd think "unity" was the right 
> word.
> 
> -Lars

# S: (n) singularity, uniqueness  (the quality of being one of a kind) 
"that singularity distinguished him from all his companions"
# S: (n) singularity (strangeness by virtue of being remarkable or unusual)

http://wordnetweb.princeton.edu/perl/webwn?s=singularity

Then again

# In mathematics, a singularity is in general a point at which a given 
mathematical object is not defined, or a point of an exceptional set 
where it fails to be well-behaved in some particular way, such as 
differentiability. ...
en.wikipedia.org/wiki/Singularity_(maths)

# the state of being singular, distinct, peculiar, uncommon or unusual; 
a point where all parallel lines meet; a point where a measured variable 
reaches unmeasurable or infinite value; the value or range of values of 
a function for which a derivative does not exist; a point or region in ...
http://en.wiktionary.org/wiki/singularity

# location where the fabric of space or spacetime suffers a devastating 
rupture.
http://www.pbs.org/wgbh/nova/elegant/glossary.html

Which now leaves me totally confused as to correct usage! :-)