The state of being difficult to account for; the state of being inexplicable.
The state of being singular, distinct, peculiar, uncommon or unusual.
An unusual action or behaviour.
A point where all parallel lines meet.
Celibacy, singleness (as contrasted with marriage).
A point where a measured variable reaches unmeasurable or infinite value.
The value or range of values of a function for which a derivative does not exist.