A new military recruit.
I sometimes hear baseball announcers refer to certain professional MLB players as "youngsters." These players are generally in their early 20s, though age itself does not always seem to be the only criteria for being called a youngster.
I have never liked the word "youngster" when used to describe adults. Certain baseball announcers have a way of using that word to make some players sound like children in little league.
Words used to describe young people are often derogatory when used later in life or in other contexts.
A "minor" is used to describe someone under 18, but it’s also used to describe something of lesser significance.
Similarly the phrase "small fry" is used (affectionately, I would think) to describe a young person, but to describe a company or a nation as small fry is demeaning.
"Sprog" to me does not glow with positive implications. A mix between spry and frog? Splat and grog? Spat and blog? It has a bit of a croaking sound to it.
