suus
suus, sua, suum
adjective
su-us · /ˈsu.us/
his own, her own, their own
The reflexive possessive: it looks back to the subject of the sentence, unlike eius — his, of someone else.
in the texts
Meménto (pro vivis) suísque, suárum, suæ, sua
Evangelium ultimum (Ioann. 1, 1-14) sui
external dictionary: Logeion