Popple has a number of meanings. It can be used to mean the poplar tree, cornfield weeds, or to make a constant popping sound.
It can also be used as a noun for ‘a rolling or rippling of water’ or ‘a choppy body of water’.
Popple is considered imitative – it reproduces the sound of the thing it is describing.
“The sound of waters dropping, poppling, splashing, trickling.”
– C. J. Cornish, The Naturalist on the Thames. 1902
It is thought to originate from the Middle Dutch word popelen, meaning ‘to murmur’ or ‘to mumble’. The OED also gives comparisons with the West Frisian word popelje, meaning ‘to throb’ or ‘to bubble up’, and the regional German word poppeln, meaning ‘to bubble’.
The earliest usage recorded by the OED was c1400. And it isn’t just used for descriptions of the natural world.
“His brains came poppling out like water.”
– Charles Cotton, Burlesque upon burlesque. 1675
- The Oxford English Dictionary Online