English
pseudosphere
From pseudo- + sphere.
Proto-Indo-European *sperH- ‘to kick, rebound, move convulsively’
…
Latin sphaera ‘ball, globe, celestial sphere’
Late Latin sphēra
Old French sphere ‘sphere (shape)’
Middle English spere ‘the cosmos, outer space’
English sphere
Today it means
noun A surface generated by rotating a tractrix about its asymptote; a tractricoid
Language periods are conventional ranges, not dates for this word.
Etymograph / pseudosphere