The most common and most likely answer to this crossword clue is the 11 letter word BATHYSPHERE
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More clues leading to the result BATHYSPHERE
Buddy explains!
The straight part
We know that "Get immersed, certainly eliminating interior pressure, in this thing?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case get immersed, certainly eliminating interior pressure, in this thing? = bathysphere.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 BATHYSPHERE mean?
BATHYSPHERE noun- A spherical steel deep-diving chamber with perspex windows, in which persons are lowered to the depths by a cable to study the oceans and deep-sea life; the precursor to the bathyscaphe