arduous /ärˈdū-əs/

1. Steep, difficult to climb
2. Difficult to accomplish
3. Laborious

ardˈuously adverb

• timber-mare
• timbermen
• timbers
• timber-toes
• timber tree
• timber trees
• timber wolf
• timber wolves
• timberyard
• timberyards
• timbre
• timbrel
• timbrel'd
• timbrels
• timbres
• timbrologies
• timbrologist
• timbrologists
• timbrology
• timbromania
• timbromaniac
• timbromaniacs
• timbromanias
• timbrophilies
• timbrophilist