Lexical Definition

‎ἐπιδιατάσσομαι‎ epidiatássomai (ep-ee-dee-ah-tas'-som-ahee) to add to ^G:V
middle voice from ‎ἐπί‎ and ‎διατάσσω‎

add to.

• to appoint besides, i.e. supplement (as a codicil)

Abbott-Smith

*† ἐπι-δια-τάσσομαι
to add provisions to a document: Ga 3:15 (cf. ἐπιδιαθήκη, a second will, F1J, BJ, ii, 2, 3; the word is used of wills in π., cf. Deiss., LAE, 87).†

Abbott-Smith References

Liddell-Scott-Jones

ἐπιδιατάσσομαι-τάσσομαι,

make additions to a will, NT.Gal.3.15.

_{LSJ Scripture Refs: Gal.3.15}