She answered the phone and, to her great 'joy', heard her son's voice on the line. [=she felt very happy when she heard her son's voice]
“You've spent hours looking for it. Any 'joy'? [='luck']” “No 'joy' whatsoever, I'm afraid. I can't find it.”
They were 'shouting/jumping for joy'. [=they shouted/jumped because they were very happy]
(..) You're surrounded by enemies, thousands of them. You're going to kill them all by yourself? You've lost, Cersei. It's the only joy I can find in all this misery. Pick the pace up. Keep going. Keep it moving! Now, that is a sorry attempt at a siege. (..)2016 TvShow: Game of Thrones Title: The Broken Man Season: 6 Episode 7