arduous /ärˈdū-əs/

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

ardˈuously adverb

• Prince Albert
• Prince Alberts
• prince-bishop
• prince-bishops
• Prince Charming
• prince consort
• prince consorts
• princed
• princedom
• princedoms
• princehood
• princehoods
• prince-imperial
• princekin
• princekins
• princelet
• princelets
• princelier
• princeliest
• princelike
• princeliness
• princelinesses
• princeling
• princelings
• princely