The most common and most likely answer to this crossword clue is the 7 letter word MILKMAN
I've seen this crossword clue in The Times
M
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L
K
M
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More clues leading to the result MILKMAN
Buddy explains!

The straight part
We know that "Float round person?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case float round person? = milkman.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 MILKMAN mean?
MILKMAN noun- A man who delivers milk to households and sometimes businesses early in the morning.