default (verb) – to fail to meet an obligation or lose by failing to compete
BREAKDOWN: DE- (from) + FAL- (fail)
— a default is also a value used when none is provided or a selection made in the absence of an alternative
This word is built on the root FAL-, which means to fail or to deceive.
Common FAL- words include fault, fail, failure, false, and falsehood.
More esoteric FAL- words include fallibility.