Alternative form of hard nut to crack

Synonym of bitter pill to swallow

plural of difficult pill to swallow

plural of difficult nut to crack

The state of being difficult, or hard to do. / An obstacle that hinders achievement of a goal. / (sometimes in the plural) Physical danger from the environment, especially with risk of drowning

plural of difficulty

(colloquial) a series of frustrations

(archaic) With difficulty; not easily.

The relative difficulty of completing a task or objective. / (video games) A variable setting in a video game determining how challenging it is to play.

In a way that requires significant effort.