Abbott-Smith Manual Greek Lexicon
δευτεραῖος (G1206)
1 * δευτεραῖος , -α, -ον ( δεύτερος ), adj. with adverbial sense; on the second day : δευτεραῖοι ἤλθομεν , Ac 28:13 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain