impure
adj.containing something bad or unwanted. In programming, it means a value or data that is not in the correct format or is missing.
adj.containing an undesirable or incorrect component. In a programming context, it describes a value that fails to meet a specific type or validation constraint.
“The function returns an impure value if the input is wrong.”
“The system checks for impure data before it processes the transaction to prevent errors.”
“In functional programming, an impure function is one that produces different results for the same input or has side effects that alter the program's state.”
“The woman is not a Brahmin and is considered sexually “impure” – because she is not a virgin – as per prevailing norms.”
From Middle French impur, from Latin impūrus.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.