will-o'-the-wisp.

1. A wandering light said in folklore to appear over marshes or boggy ground at night.

2. A hope, person, or goal that seems attractive but remains difficult or impossible to reach.

Use it for

Words that belong together

• marsh will-o’-the-wisp
• a will-o’-the-wisp light
• follow a will-o’-the-wisp
• chase a will-o’-the-wisp
• a political will-o’-the-wisp

On the page

A will-o’-the-wisp flickered beyond the reeds and vanished when he turned.

The promised cure became a will-o’-the-wisp that kept the village working through winter.

Usage notes

The literal sense belongs to folklore; figurative use names an alluring but elusive or misleading goal. The phrase is often hyphenated and conventionally set. Sense 2: The figurative sense is conventional and often warns that an enticing aim is illusory or unreachable.