dense, doltish, dumb, hebetudinous, obtuse, stupid, thickheaded, thick-witted.
Ruth's parents are not coarse hypocrites; on the other hand, they are not so blockheadedly proud that they cannot ameliorate the effects of sincere misjudgments that were only premised on their delicacy: Ruth finds Martin and abases herself before him, begging him to reconsider her.
The Ministry, which should have been responsible for clean food, instead supported and connived at the worst operations in farming and animal husbandry, derided accurate warnings and were blockheadedly ignorant of good practice elsewhere.