Art Owen's exemplary 2001 monograph on empirical likelihood introduces
phantom observations at plus and minus infinity to cope with tail
probabilities in the treatment of EL for quantiles. Somewhat as an
afterthought, a few pages later, Owen refers to such points as "undata."
Having found similar contrivances useful for some recent work on density
estimation, I was immediately struck by the aptness of the term.
A little further Googology revealed that there was a whole world
of real, living undata. In botany and zoology undata is a Linnean epithet
meaning wavy-edged. I've collected a few examples to illustrate the
astonishing variety of undata:
Micromelo Undata: Sea Slug (Australia).
Sylvia Undata: Dartford Warbler (UK).
Dichorisandra Undata: Seersucker Plant (Peru).
Xylophanes Undata: Silk Moth (Ecuador).
Popa Undata: Praying Mantis (South Africa).
Nerita Undata: Wave Marked Nerite (Indo-West Pacific).
Megatoma undata ussuriensis (Moscow Region)
Pyrgota Undata: Waved Light Fly (South Carolina USA).
Montipora Undata: Montipora Stony Coral (Indonesia).
Banksia Undata (Western Australia).