Not 100% solid (4)
I believe the answer is:
iffy
(Other definitions for iffy that I've seen before include "Chancy, suspect" , "Informally dubious, not definite" , "Dubious, risky (inf.)" , "Uncertain (colloq.)" , "Not certain, doubtful" .)
I believe the answer is:
iffy
(Other definitions for iffy that I've seen before include "Chancy, suspect" , "Informally dubious, not definite" , "Dubious, risky (inf.)" , "Uncertain (colloq.)" , "Not certain, doubtful" .)