The most common and most likely answer to this crossword clue is the 7 letter word RANCHES
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More clues leading to the result RANCHES
Buddy explains!

The straight part
We know that "farms across the Atlantic" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case farms across the atlantic = ranches.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 RANCHES mean?
RANCHES noun- A large plot of land used for raising cattle, sheep or other livestock.
- A small farm that cultivates vegetables and/or livestock, especially one in the Southwestern United States.
- A house or property on a plot of ranch land.
- Ranch dressing.