The most common and most likely answer to this crossword clue is the 7 letter word TWITTER
T
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More clues leading to the result TWITTER
- Laugh about women’s idle talk
- Talk excitedly and giggle, drinking whisky
- Do bird? Third time, not second, for conman
- Means of communication, 28
- Laugh about wife’s social medium
- Laugh about start of written communication for a lark, perhaps
- Laugh about Washington’s leader — what’s he on?
- Wire three times? Strange way to send short message
- Giggle about women’s social medium
- Tons write on the move about time in networker’s site
Buddy explains!

The straight part
We know that "messaging service" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case messaging service = twitter.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 TWITTER mean?
TWITTER verb- (sometimes proscribed) To tweet; to post an update to Twitter.
- The sound of a succession of chirps as uttered by birds.
- A tremulous broken sound.
- A slight trembling of the nerves.
- Unwanted flicker that occurs in interlaced displays when the image contains vertical detail that approaches the horizontal resolution of the video format.
- To utter a succession of chirps.
- (of a person) To talk in an excited or nervous manner.
- To make the sound of a half-suppressed laugh; to titter; to giggle.
- To have a slight trembling of the nerves; to be excited or agitated.
- To twit; to reproach or upbraid.