Difficult and Vigorous

Difficult adjective - Requiring considerable physical or mental effort.

Vigorous and difficult are semantically related. In some cases you can use "Vigorous" instead an adjective "Difficult".

Nearby Word: difficulty

Vigorous adjective - Having active strength of body or mind.

Difficult and vigorous are semantically related. Sometimes you can use "Difficult" instead an adjective "Vigorous".

Nearby Words: vigor, vigour, vigorously