Answer: potofgold

AnswerCrossword Clue
POTOFGOLD

Mythical rainbow prize

POTOFGOLD

Huge windfall

POTOFGOLD

Imaginery treasure.

POTOFGOLD
Something sought but never found.
POTOFGOLD
Elusive goal
POTOFGOLDRainbow's end?
POTOFGOLDRainbow's fabulous bonanza