feeble minded

For example, in a marriage of double cousins the wife was "feeble minded" and the six children were of inferior mentality.

Sometimes I think I'm not half as feeble minded as they say I am.

It will be limited to five hundred copies and, of course, sold only to the feeble minded.

But if Mrs. Colton had deliberately chosen the spot, with malice aforethought, the place for her was a home for the feeble minded.

I think she threatened to have me sent to an Orphans' Home, or a hospital for the feeble minded.

So spoke the well meaning and feeble minded prince, and the prior bowed in acquiescence.