english
1
general::
Phrase(s): couldn’t pour water out of a boot (if there was instructions on the heel) Rur. stupid. • I won’t say Jim is dumb, but he couldn’t pour water out of a boot. • Jane couldn’t pour water out of a boot if there was instructions on the heel—and she’s the smartest one in her family!
McGrawhill's American Idioms And Phrasal Verbs