1: ἐπιούσιος
(Strong's #1967 — Adjective — epiousios — ep-ee-oo'-see-os )

is found in Matthew 6:11; Luke 11:3 . Some would derive the word from epi, "upon," and eimi, "to be," as if to signify "(bread) present," i.e., sufficient bread, but this formation is questionable. The same objection applies to the conjecture, that it is derived from epi, and ousia, and signifies "(bread) for sustenance." The more probable derivation is from epi, and eimi, "to go," (bread) for going on, i.e., for the morrow and after, or (bread) coming (for us). See the RV marg. This suits the added semeron, "to-day," i.e., the prayer is to be for bread that suffices for this day and next, so that the mind may conform to Christ's warning against anxiety for the morrow. Confirmation of this derivation is also to be found in the word epiouse, in the phrase "the next day," Acts 7:26; 16:11 .

2: ἐφήμερος
(Strong's #2184 — Adjective — ephemeros — ef-ay'-mer-os )

signifies "for the day" (epi, "upon, or for," hemera, "a day," Eng., "ephemeral"), James 2:15 .

3: καθημερινός
(Strong's #2522 — Adjective — kathemerinos — kath-ay-mer-ee-nos' )

means, lit., "according to" (kata) "the day" (hemera), "day by day, daily," Acts 6:1 .

Luke 11:3Acts 3:216:51—Corinthians 15:31Hebrews 7:272—Corinthians 4:162—Peter 2:82—Corinthians 3:14,15James 4:13Romans 11:8 Luke 21:37Acts 5:42Acts 17:17Hebrews 3:13