may you live long! (response to a younger person's salutation)

may you live long!

(of something) to be devastated, to go away entirely, to be gone for good, to pass away, to vanish, be missing, be lost, disappear

be considered dead while alive (an expression of displeasure and snapping of all ties)

to remain or continue alive, to enjoy a long life

remain very busy or involved, work very hard

better lose half than all