acrobatics

The story

1. Proto-Indo-European*h₂eḱ-
2. Proto-Indo-European*h₂eḱrós
3. Proto-Hellenic[Term?]
4. Ancient Greekᾰ̓́κρος (ắkros)
5. Proto-Indo-European*gʷem-
6. Proto-Indo-European*gʷm̥yéti
7. Proto-Hellenic*gʷəňňō
8. Proto-Indo-European*gʷeh₂-
9. Proto-Hellenic*égʷēn
10. Ancient Greekβαίνω (baínō)
11. Ancient Greekβᾰτός (bătós)
12. Ancient Greekἀκροβάτης (akrobátēs)
13. Frenchacrobate
14. Englishacrobat
15. English todayacrobatics

From acrobat + -ics. By surface analysis, acrobatic + -s.