un ‧ rea ‧ lis ‧ tic /ˌʌnrɪəˈlɪstɪk◂/ BrE AmE adjective
[ Word Family: noun : ↑ realism , ↑ realist , ↑ reality , ↑ unreality , ↑ realization ; adverb : ↑ real , ↑ really , ↑ realistically ≠ ↑ unrealistically ; adjective : ↑ real , ↑ unreal , ↑ realistic ≠ ↑ unrealistic ; verb : ↑ realize ]
unrealistic ideas or hopes are not reasonable or sensible
it is unrealistic to do something
It is unrealistic to expect these changes to happen overnight.
Some parents have totally unrealistic expectations of teachers.
—unrealistically /-kli/ adverb