The most common and most likely answer to this crossword clue is the 6 letter word ROUTER
I've seen this crossword clue in Financial Times
R
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Buddy explains!
The straight part
We know that "device for data delivery" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case device for data delivery = router.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 ROUTER mean?
ROUTER noun- Someone who routes or directs items from one location to another.
- Any device that directs packets of information using the equivalent of Open Systems Interconnection layer 3 (network layer) information. Most commonly used in reference to Internet Protocol routers.
- A device that connects local area networks to form a larger internet by, at minimum, selectively passing those datagrams having a destination IP address to the network which is able to deliver them to their destination; a network gateway.
- (electronic design automation) In integrated circuit or printed circuit board design, an algorithm for adding all wires needed to properly connect all of the placed components while obeying all design rules.
- A power tool used in carpentry for cutting grooves.
- A plane made like a spokeshave, for working the inside edges of circular sashes.
- A plane with a hooked tool protruding far below the sole, for smoothing the bottom of a cavity.
- To hollow out or cut using a router power tool.