We define the term as follows...
fitment : The mechanical configuration of the attachment end of a flow channel, for means of attaching to another medium or appliance.
If you seek a compatible fitting, the fitment to which you are attaching is what matters.
Many fittings have more than one type of fitment.
Coming soon: A [reasonably] complete listing of all of the fitments described here at PipeandHose.com.
Please stand by as we endeavor to complete our mission...