nounadjectiveadverb

ett fel

mistake

När något inte är rätt eller när man gör något på ett sätt som inte stämmer.

The word fel has two primary meanings in Swedish:

Error, mistake, or fault: Used to describe something that is incorrect, not functioning properly, or a lapse in judgment. For example, "ett räknefel" (a calculation error) or "det var mitt fel" (it was my fault).
Wrong: Used as an adjective to indicate that something is not right or accurate, or as an adverb meaning incorrectly. For example, "du har fel" (you are wrong) or "gå åt fel håll" (to walk in the wrong direction).

Grammar: It is a neuter noun (ett-word). In the singular, it is "ett fel", and in the plural, it remains "fel". The definite form is "felet" (singular) and "felen" (plural). As an adjective/adverb, it is indeclinable.
Word origin: It stems from the Old Norse word fell, which originally meant a falling away or a collapse, related to the verb falla (to fall). The meaning shifted from physical falling to a moral or intellectual "fall" or error.