The most common and most likely answer to this crossword clue is the 6 letter word INFLUX
I've seen this crossword clue in Independent
I
N
F
L
U
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More clues leading to the result INFLUX
- Arrival at home with illness by ten
- Mass invasion during times after disease
- Arrival of unknown number following home sickness
- Large number of people entering new complaint of aches and pains in backside?
- Ten with hip complaint, all coming together
- Flood in motion
- Stream data endlessly, given amount of light
- New bug caught by team going up stream
- Rush among ten catching disease
- Flood at home, getting cross after complaint
Buddy explains!

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 INFLUX mean?
INFLUX noun- A flow inward or into something; a coming in.
- That which flows or comes in.
- Influence; power.