The state of being difficult, or hard to do.
Physical danger from the environment, especially with risk of drowning
An obstacle that hinders achievement of a goal.
An objection.
An awkward situation or quarrel.
That which cannot be easily understood or believed.
A change, especially in one's life or fortunes.
Regular change or succession from one thing to another, or one part of a cycle to the next; alternation; mutual succession; interchange.