In angling, an artificial fly which is allowed to sink: in distinction from a dry-fly, or floating fly.(noun)
The Century Dictionary (Public Domain)
Use "wet-fly" in a sentence
"When the hatch slowed down a little, they preferred a size 14 nymph swung down and across the current wet-fly–style."
"With a moderate-action rod and double-taper line, it gives surprising range, and it's perfect for wet-fly fishing, where false casting can dry the fly and inhibit sinking."
"But the old style of wet-fly fishing will often catch trout when floating patterns fail."