Challenging and Humdrum

Challenging adjective - Requiring considerable physical or mental effort.

Humdrum and challenging are semantically related. In some cases you can use "Humdrum" instead an adjective "Challenging".

Nearby Words: challenge, challenged, challenger

Humdrum adjective - Causing weariness, restlessness, or lack of interest.

Challenging and humdrum are semantically related. Sometimes you can use "Challenging" instead an adjective "Humdrum".