over-optimistic
adjective
(alsooveroptimistic)ukustoohopeful, or tooreadytobelievethat good things willhappenin thefuture:
Hefearsthatanalystsare being over-optimistic aboutfuturecompanyearnings.
Planning for theprojectwasgrosslyinadequateand overoptimistic,particularlyasregardsstaffing.