The trait of not being dependable or reliable(noun)
WordNet. Princeton University. 2010.
Use "undependability" in a sentence
"There is real diversity in this village of some 300 people which encompasses 527 acres, but the level of quality and consistency is almost unmatched in Burgundy, a region whose wines sometimes remind me of British sports cars of the 1960s in their fickleness and undependability, although the wines are more predictable today than in years past."
"And sure enough, my intrinsic undependability bursts forth: I can't shake the notion that gender wasn't an issue until the Clinton campaign MADE it an issue!"
"Yes, the main problem with the bus system is the inconvenience factor for most car owners (in terms of lack of parking, undependability of service, and the fact that the trip usually takes longer than by car)."