Humdrum and Well-worn

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

Well-worn and humdrum are semantically related In some cases you can use "Well-worn" instead an adjective "Humdrum".

Well-worn adjective - Used or heard so often as to be dull.

Humdrum and well-worn are semantically related in uninteresting topic. Sometimes you can use "Humdrum" instead an adjective phrase "Well-worn", if it concerns topics such as boring.