1. Want of proficiency or improvement.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• ynproficiency,
• hnproficiency,
• jnproficiency,
• 8nproficiency,
• 7nproficiency,
• ubproficiency,
• ujproficiency,
• uhproficiency,
• unoroficiency,
• unlroficiency,
• un-roficiency,
• un0roficiency,
• unpeoficiency,
• unpdoficiency,
• unpfoficiency,
• unptoficiency,
• unp5oficiency,
• unp4oficiency,
• unprificiency,
• unprkficiency

• impotence,
• inefficiency,
• weakness,
• ineptitude,
• fumbling,
• deficiency,
• clumsiness,
• insufficiency,
• incapacity,
• inability,
• dullness,
• incompetency.

The adjective form of "unproficiency" is "unproficient".

The plural form of the word "unproficiency" is "unproficiencies"

The singular form of "unproficiency" is "unproficient"