The most common and most likely answer to this crossword clue is the 7 letter word POSTMAN
I've seen this crossword clue in The Times
P
O
S
T
M
A
N
More clues leading to the result POSTMAN
- One getting the sack maybe after us
- Job with island worker delivering letters
- Child’s play, this innings from one used to handling deliveries?
- Job obtained by graduate — not primarily one who goes the rounds?
- Online comments criticise engaging staff for game
- Chap with letters after name welcoming graduate
- Early visitor to house after castle, say
- One delivering mail — not spam for a change
- Bringer of tidings needs support ? Mother Nature, primarily
- No stamp fixed? He won’t deliver!
Buddy explains!

The straight part
We know that "Child’s play" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case child’s play = postman.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does POSTMAN mean?
POSTMAN noun- Someone (implied male) who delivers the post (mail) to, and/or collects the post from, residential or commercial addresses, or from public mailboxes.
- One of the two most experienced barristers in the Court of Exchequer, who have precedence in motions, so called from the place where he sits, the other of the two being the tubman.