noun
tench
TENCH/tentʃ/
A freshwater Eurasian fish related to carp.
A tench swims slowly through the weeds in the pond.

Etymology
Latin tinca was already a name for this fish, so the connection is continuity of naming rather than a descriptive image. The supplied evidence gives no deeper explanation of the name.
In context
I've caught some tench out of this pond.
More examples
- The angler catches a tench near the muddy bank.
- Tench thrive in still water with plenty of vegetation.
- Several tenches feed along the bottom of the lake.
Forms
tench · tenches