Q From Jonathan Downes: I wonder if you could tell me the origin of ruthless and gormless? Why are the opposites missing — why do we not describe someone, for example, as full of gorm?
A What has happened is that the root words have vanished, leaving the negatives behind. There are quite a number of these orphaned negatives. Comic writers have often exploited this fact to startle readers, as in P G Wodehouse’s “I could see that, if not actually disgruntled, he was far from being gruntled” (from The Code of the Woosters).
Gormless is now mainly an informal British English word that describes somebody foolish, lacking sense or initiative. This comes from a defunct term, usually spelt gaum, a dialect word meaning care or attention; in turn this derives from an Old Norse word gaumr. Though rarely recorded, at one time gaum-like was also around, for someone with an intelligent look about them. Curiously, the verb to gorm also existed, which meant to stare vacantly, implying almost the opposite; but this may be related to the Irish gom for a stupid-looking person and so may be unconnected with the other sense of gorm.
Ruthless is easier, since ruth was a well-attested Middle English word for a feeling of pity or compassion. This was formed about the twelfth century from the Anglo Saxon noun and verb rue, with the same sense (we still have the verb, of course, with the closely related idea of regret). The adjective ruthless appeared in the fourteenth century. The noun is now archaic, but the adjective survived.