Posted by kazvorpal on August 12, 2010
A decisive blow or (by metaphor) remark, or something similarly powerful
Possibly a tent revival word, but reached popularity as a boxing term.
Every second or two there’d come a glare that lit up the white-caps for a half a mile around, and you’d see the islands, looking dusty through the rain, and the trees thrashing around in the wind; then comes a H-WHACK!-bum! bum! bumble-umble-um-bum=bum-bum-bum- and the thunder would go rumbling and grumbling away, and quit – and then RIP comes another flash and another sockdolager.
—Mark Twain, The Adventures of Huckleberry Finn
Invented in the 19th century, “sock”, as to hit, plus perhaps a variation on “doxology”, which of course is a Christian term for praising God.