noun
dereliction
dair-uh-LIK-shun/ˌderəˈlɪkʃn/
Serious neglect of an obligation or responsibility.
The lifeguard commits a dereliction of duty by ignoring a struggling swimmer.

Etymology
Leaving something entirely behind supplies the central idea of abandonment. Applied to duty, this becomes neglecting or failing to carry out a responsibility rather than abandoning a physical thing.
In context
they told me if I filed a claim that I've been raped I'd also be charged with dereliction of Duty for leaving my weapon unattended
More examples
- Failing to investigate the abuse reports was a serious dereliction of duty.
- The board dismissed the director for repeated derelictions of duty.
- Leaving the children unsupervised was a dereliction of her responsibility as their caregiver.
Forms
dereliction · derelictions
derelict adjective — Seriously neglectful of an assigned duty.
Similar words
- neglect
- Neglect covers inadequate care, whether or not a duty exists.
- negligence
- Negligence emphasizes a failure to exercise reasonable care.