Deecherless / Deechy = both are adjectives and both have equal 'standing' depending on the context in which they are being used. One is certainly not 'better' than the other.

What about 'deechable' / 'undeechable' ? I have many students who fall into that adjectival category, lol.

Noun forms could be 'deechability' / 'undeechability' haha. Contact Merriam Webster and see if they are interested, lol.