Vincent's NT Word Studies
21. All the Athenians. No article. Lit., "Athenians, all of them." The Athenian people collectively.Strangers which were there (oi epidhmountev xenoi). Rev., more correctly, the strangers sojourning there. See on 1 Pet. i. 1.
Spent their time (eukairoun). The word means to have good opportunity; to have leisure: also, to devote one's leisure to something; to spend the time. Compare Mark vi. 31; 1 Cor. xvi. 12.
Something new (ti kainoteron). Lit., newer: newer than that which was then passing current as new. The comparative was regularly used by the Greeks in the question what news? They contrasted what was new with what had been new up to the time of asking. The idiom vividly characterizes the state of the Athenian mind. Bengel aptly says, "New things at once became of no account; newer things were being sought for." Their own orators and poets lashed them for this peculiarity.
Aristophanes styles Athens the city of the gapers ("Knights," 1262). Demades said that the crest of Athens ought to be a great tongue.
Demosthenes asks them, "Is it all your care to go about up and down the market, asking each other, 'Is there any news?'" In the speech of Cleon to the Athenians, given by Thucydides (iii., 38), he says: "No men are better dupes, sooner deceived by novel notions, or slower to follow approved advice. You despise what is familiar, while you are worshippers of every new extravagance. You are always hankering after an ideal state, but you do not give your minds even to what is straight before you. In a word, you are at the mercy of your own ears."
Robertson's NT Word Studies
17:21 {Spent their time} (eukairoun). Imperfect active of eukairew. A late word to have opportunity (eu, kairos) from Polybius on. In the N.T. only here and #Mr 6:31. They had time for,.etc. this verse is an explanatory parenthesis by Luke. {Some new thing} (ti kainoteron). Literally "something newer" or "fresher" than the new, the very latest, the comparative of kainos. Demosthenes (_Philipp_. 1. 43) pictures the Athenians "in the agora inquiring if anything newer is said" (punqanomenoi kata ten agoran ei ti legetai newteron). The new soon became stale with these itching and frivolous Athenians.