Noun for a fault, error, or blameworthy point, especially in set phrases such as 非を認める and 非がある.
He honestly admitted his own fault.
この件では、どちらに非があるのか分からない。
In this matter, I do not know which side is at fault.
unfavorable situation; disadvantage; things going badly
Mostly literary or fixed-phrase use for a situation turning against someone; commonly seen in expressions like 形勢非なり.
形勢非なりと見て、彼らは撤退を決めた。
Seeing that the situation was turning against them, they decided to withdraw.
Prefix attached mainly to Sino-Japanese nouns or noun-like bases to mean 'not', 'non-', or 'outside the normal category', as in 非公開 and 非公式. Often has a formal or written tone.
この会議は非公開で行われる。
This meeting will be held behind closed doors.
非正規雇用で働く人が増えている。
The number of people working in non-regular employment is increasing.
He admitted his fault and apologized.
The company plans to hold the person in charge accountable for the mistake.
未 means 'not yet' in a temporal sense, as in 未完成, while 非 carries no time meaning and instead marks something as outside a category, as in 非公式.
否 (ひ) is a noun meaning 'no/a negative answer', while 非 (ひ) is a prefix/noun meaning 'wrong, fault, or not-' and the two are easily mixed up because they share the reading ひ.
非 and 被 share the reading ひ but 非 is a negation prefix meaning 'non-/un-' (非常識), while 被 marks the recipient of an action (被害者).
private; non-public; closed
informal; unofficial
lack of common sense; senselessness; absurdity
part-time work; non-regular employment
unjust; inhuman; outrageous
cold-hearted; callous; unfeeling; cruel · insentient; inanimate
emergency; time of emergency
illegal; unlawful
not for sale; free item; promotional item
asymmetry; lack of symmetry
non-nuclear; anti-nuclear
delinquency; misconduct
tax-exempt; tax-free
powerless; helpless; incompetent
extraordinary; remarkable; uncommon
asynchronous
unpatriotic person; traitor
illogicality; irrationality
nonlinear; non-linear
off duty; not on duty
impoliteness; rudeness; discourtesy
non-ferrous
unnatural death; untimely death
non-destructive
unreasonable; illogical
very; extremely; exceedingly
nonmetal