assumptioneer 

An assumptioneer is someone who works in a field very similar to that of an engineer but they do not have tons and tons of accurate data available to make decisions so they have to make lots of assumptions, hence this makes them an assumptioneer - doing assumptioneering work.

Project Manager - How is the work progressing on the facility design?
Design Manager - Jon has been struggling with a lack of data but as we all know he is a great assumptioneer
Project Manager - ok as long as we clearly document all our assumptions in a concept document should be fine for now

assumptioneer by cj2017 December 9, 2017

assumptioner 

One who hails (comes) from the Catholic school Our Lady of Assumption

There are a lot of assumpionters at my school.

assumptioner by Anonymous October 4, 2003

AssumptionWare 

Stands for Assumption Software.

Software which performs actions that it assumes is OK with the user. An example of AssumptionWare would be a program that installs into a directory with no option for the user to specify a different one. Another example would be a program that writes log files with no
option to disable.

Windows can be considered AssumptionWare, since it automatically installs Internet Explorer without option.

AssumptionWare by The Sniffing Accountant March 14, 2008