What is the origin for the idiom back-handed compliment?

Answer 1

The term back-handed is the key to the origin of the term. It pre-modifies hidden negative intentions/actions (such as sarcasm, cutting remarks, speech acts, etc.). 'Back-handed compliment' just became a common term that emerged for such 'compliments', but statements such as "that was back-handed" were also used. I believe that back-handed refers to a slap/hit, in that one can perceive a typical strike, but the using the back of the hand disguises what's coming and was considered insulting and unsportsmanlike (so it becomes synonymous with being sly and using trickery to harm another person).