arduous /ärˈdū-əs/

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

ardˈuously adverb

• bombinations
• bombing
• bombings
• bomb-ketch
• bomblet
• bomblets
• bombo
• bombora
• bomboras
• bombos
• bombproof
• bombproofs
• bombs
• bombshell
• bombshells
• bombsight
• bombsights
• bombsite
• bombsites
• bomb squad
• bomb-vessel
• bomb-vessels
• bombycid
• Bombycidae
• bombycids