arduous /ärˈdū-əs/

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

• pass away
• pass-back
• pass-backs
• pass band
• pass bands
• passbook
• passbooks
• pass by
• pass-check
• pass-checks
• pass current
• pass degree
• pass degrees
• passed
• passed master
• passed midshipman
• passed pawn
• passed pawns
• passemeasure
• passemeasures
• passement
• passemented
• passementerie
• passementeries
• passementing