Adjective ateknos (childless) in the Gospels-Acts

(Translation from NRSV with a few modifications for a more literal meaning)

Luke

20: 28and asked him a question, "Teacher, Moses wrote for us that if a man's brother dies, leaving a wife, but he is childless (ateknos), the man shall marry the widow and raise up children for his brother.
20: 29Now there were seven brothers; the first married, and died childless (ateknos);