arduous /ärˈdū-əs/

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

ardˈuously adverb

ardˈuousness noun

• sepals
• separabilities
• separability
• separable
• separableness
• separablenesses
• separably
• separata
• separate
• separated
• separate development
• separate developments
• separately
• separate maintenance
• separateness
• separatenesses
• separates
• separate school
• separate schools
• separate the men from the boys
• separate the sheep from the goats
• separate the wheat from the chaff
• separating
• separation
• separation allowance