This paper aims to analyse four significant words of the same root used in the Greek versions of the book of Sirach: ἐνδελεχίζω, ἐνδελεχής, ἐνδελεχισμός, ἐνδελεχῶς. The approach is chiefly philological and consists in comparing the Greek texts with extant Hebrew fragments. Furthermore, the paper explores the specific use of this word group in different occurrences in LXX Sirach against the background of the translated books of the Septuagint and non-biblical Greek, inscriptions included.