ETYM Latin arduus steep, high; akin to Irish ard high, height.
1. Characterized by toilsome effort to the point of exhaustion; especially physical effort; SYN. backbreaking, grueling, gruelling, hard, heavy, laborious, labourious, punishing, toilsome.
2. Difficult to accomplish; demanding considerable mental effort and skill.
3. Taxing to the utmost; testing powers of endurance; SYN. straining, strenuous. + prikaži više

Having concealed difficulty; SYN. tricky.
1. Tending to catch the interest or attention
2. Easily retained in the memory
3. Fitful, irregular
4. Tricky

ETYM From Difficulty.
1. Not easy; requiring great physical or mental effort to accomplish or comprehend or endure; SYN. hard.
2. Requiring much effort and trouble.

1. Able to make fine distinctions
2. Faint and difficult to analyze

1. Not given to gentleness or sentimentality
2. Physically toughened; SYN. toughened.
3. Tough to cut or chew.

In an arduous manner.

With difficulty.