The most common and most likely answer to this crossword clue is the 5 plus 3 letter word SPACE BAR
I've seen this crossword clue in The Sunday Telegraph
S
P
A
C
E
B
A
R
More clues leading to the result SPACE BAR
- Key area, watering hole
- Key opening part of court
- What's often depressed after a period?
- Key establishment selling out-of-this-world drinks?
- Key boozer lacking atmosphere perhaps
- Key amenity Virgin Galactic might offer
- Stretch bra out of shape? Nothing is revealed when it’s pressed
- On counter, room key
- Used by writer, it gives no impression of character
- Key place for out-of-this-world drinks?
Buddy explains!
The straight part
We know that "It’s used by typist, but not for letters" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case it’s used by typist, but not for letters = space bar.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.