Adjective of "challenge"
challenging
Opposite of "patient"
impatient
Opposite of "legal"
illegal
Adjective of "hope"
hopeful
Adjective of "worry"
worried
Opposite of "renewable"
nonrenewable
Noun of "apply"
applicant
Opposite of "harmful"
harmless
Opposite of "approve"
disapprove
Adjective of "create"
creative
Noun of "assign"
assignment
Opposite of "willing"
unwilling
Adjective of "value"
valuable
Noun of "confident"
confidence
Noun of "argue"
argument
Adjective of "predict"
predictable