Somewhat blockheaded; showing signs of stubbornness or lack of intelligence in a lighter or less absolute way.
From 'blockhead' plus '-ish' suffix, which softens the accusation and makes it more relative ('somewhat blockhead-like') rather than absolute like the base adjective.
The '-ish' suffix is genius for insults because it lets you say someone is 'sort of' stupid without fully committing—it's the linguistic equivalent of a shrug.
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