didapper

The story

1. Old English · derived fromdūfedoppa“diving bird, pelican”
2. Middle English · inherited fromdydoppar
3. English todaydidapper

From Middle English dydoppar, from earlier douedoppe, deuedep, dyuedap with agentive suffix -er, from Old English dūfedoppa (“diving bird, pelican”), from dūfan (“to dive”) + *doppa (“diver”) (whence modern English dop (“diving bird”)). By surface analysis, dive + dop + -er.