English
headstander
From head + stander, from their habit of swimming at a 45° angle, head pointed downwards, as if standing on their heads.
Proto-Indo-European *kap- ‘head’
…
Proto-Germanic *haubudą ‘head’
Proto-West Germanic *haubud
Old English hēafod ‘head’
Middle English heed ‘head’
English head
Today it means
noun Any of several species of South American fish, in families Anostomidae and Chilodontidae in order Characiformes.
Language periods are conventional ranges, not dates for this word.
Etymograph / headstander