FROM STRONG’S GREEK DICTIONARY (1890)

Strong’s Greek Dictionary (1890) — public domain, printed whole.

aiphnidios αἰφνίδιος — aheef-nid'-ee-os — from a compound of 1 (as a negative particle) and 5316 (compare 1810) (meaning non-apparent); unexpected, i.e. (adverbially) suddenly:--sudden, unawares.

see GREEK for 1

see GREEK for 5316

see GREEK for 1810