Synonyms of the word

formidability

• n. The state of being formidable.

difficultness

• n. The state or quality of being difficult.

difficulty

• n. The state of being difficult, or hard to do.
• n. An obstacle that hinders achievement of a goal.
• n. Physical danger from the environment, especially with risk of drowning.

toughness

• n. (uncountable) The state of being tough.
• n. (physics, of a metal) Resistance to fracture when stressed.
• n. A formidable difficulty.