| 1 | Ancient Greek | αἴσθησις | Perception from the senses, feeling, hearing,... |
| 2 | Ancient Greek | -σῐς | "suffix forming nouns" |
| 3 | Ancient Greek | -τις | Earlier form of -σις , retained after dentals δ,... |
| 4 | Proto-Indo-European | -tis | Derives abstract/action nouns from verb roots |