arduous /ärˈdū-əs/

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

• uncinus
• uncipher
• unciphered
• unciphering
• unciphers
• uncircumcised
• uncircumcision
• uncircumcisions
• untruisms
• untruly
• untruss
• untrussed
• untrusser
• untrussers
• untrusses
• untrussing
• untrussings
• untrust
• untrustful
• untrustiness
• untrustinesses
• untrusts
• untrustworthily
• untrustworthiness
• untrustworthy