mismatch
n.a situation where two things do not fit together or do not match each other. You use this when there is a difference between what you have and what you need.
n.a failure to correspond or match; a discrepancy between two or more elements. Often describes a lack of alignment between skills and requirements or supply and demand.
“There is a mismatch between his skills and the job.”
“The project failed because of a clear mismatch between the ambitious goals and the limited budget available.”
“Economists often point to a structural mismatch in the labor market, where the qualifications of the unemployed do not align with the technical requirements of vacant positions.”
Commonly paired with the preposition 'between' to identify the two conflicting elements.
“They linked this effect to prediction error, which occurs when there is a mismatch between what someone expects and what actually happens.”
“There is a mismatch between my question and the evidence provided in this study.”
From mis- + match (verb sense).
From mis- + match (noun sense).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.