björntjänst

Etymology
, used since 1891. Compare 🇨🇬, 🇨🇬, and similar forms in other languages. From a French fable (L’Ours et l’Amateur des jardins by Jean de La Fontaine) in which a tame bear wants to do his master a favor by hitting the fly who sat down on the master's forehead, but hits the fly so hard that the master too is killed.

Noun

 * 1) a disservice, a mistaken kindness, a misguided helpfulness, an attempted favor which turns out to be detrimental, or at least causes more damage than it helps