1: ἀρχή
(Strong's #746 — Noun Feminine — arche — ar-khay' )

"beginning," is used in Hebrews 6:1 , in its relative significance, of the beginning of the thing spoken of; here "the first principles of Christ," lit., "the account (or word) of the beginning of Christ," denotes the teaching relating to the elementary facts concerning Christ. See BEGIN , B.

2: στοιχεῖον
(Strong's #4747 — Noun Neuter — stoicheion — stoy-khi'-on )

is translated "principles" in Hebrews 5:12 . See ELEMENTS.