He always sees the glass as half empty rather than half full.
half baked
Frequency:
70
%
His half baked idea was quickly dismissed by the team.
half-hearted
Frequency:
60
%
She made a half-hearted attempt to finish her homework.
halfway decent
Frequency:
45
%
The movie was only halfway decent, but we still enjoyed it.
Idiomatic Expressions for half cocked
Phrase: half-cocked idea
Meaning: an ill-conceived or poorly thought-out plan or notion
Usage: His half-cocked idea to start a business without any research led to its quick failure.