The most common and most likely answer to this crossword clue is the 5 letter word TELOI
T
E
L
O
I
Buddy explains!
The straight part
We know that "extractable from Eliot’s letters (5)" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case extractable from eliot’s letters (5) = teloi.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 TELOI mean?
TELOI noun- The aim or goal.