Usage: 4 forms in 19 verses
Form Translated As     In Verse(s)
επιδεκάτων your tenth parts LXX.Num.18.28
επιδεκάτου tenth part LXX.Num.18.26
επιδέκατον a tenth LXX.Num.18.26
tenth LXX.Deut.14.28
tenth part LXX.Num.18.21LXX.Num.18.26LXX.Deut.26.12LXX.Deut.26.12LXX.Isa.6.13
tithe LXX.Deut.12.17
επιδέκατα a tenth LXX.2Chr.31.5LXX.2Chr.31.6LXX.2Chr.31.6
of your tithes LXX.Amos.4.4
tenth parts LXX.Num.18.24LXX.2Chr.31.12LXX.Mal.3.8
tithes LXX.Deut.14.23
your tithes LXX.Deut.12.11

Liddell-Scott-Jones

ἐπιδέκατος (epidekatos) a tithe G:A

ἐπιδέκατος-τος, ον,

containing an integer and one-tenth: hence . λόγος ratio of [Refs]

__II. one in ten: hence substantive -δέκατον, τό,
__II.1. tenth, tithe, Legal cited in [Refs 5th c.BC+]
__II.2. payment of [Refs] on account, [Refs 3rd c.BC+]
__II.3. payment of 10 as παρακαταβολή (which see), [Refs 3rd c.BC+] (8).640 (Peparethus, 2nd c.BC).
__II.4. additional, extra payment of onetenth, [Refs 3rd c.BC+]