The most common and most likely answer to this crossword clue is the 5 letter word TOWER
I've seen this crossword clue in The Daily Telegraph
T
O
W
E
R
More clues leading to the result TOWER
- Tall building initially tempts one in debt
- Rise of drag performer?
- Wrote about tall building
- Fortress you and I observed in rocky peak
- Keep time or we go wrong
- Building we found in shelter of hill
- One drawing a tall building
- London tourist attraction, one exerting a pull
- Wrote about in column
- Stop twerp undressing in part of castle
Buddy explains!

The straight part
We know that "Keep" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case keep = tower.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 TOWER mean?
TOWER noun- A very tall iron-framed structure, usually painted red and white, on which microwave, radio, satellite, or other communication antennas are installed; mast.
- A similarly framed structure with a platform or enclosed area on top, used as a lookout for spotting fires, plane crashes, fugitives, etc.
- A water tower.
- A control tower.
- Any very tall building or structure; skyscraper.
- Any item, such as a computer case, that is usually higher than it is wide.
- An interlocking tower.
- A strong refuge; a defence.
- A tall fashionable headdress worn in the time of King William III and Queen Anne.
- High flight; elevation.
- The sixteenth trump or Major Arcana card in many Tarot decks, usually deemed an ill omen.
- The nineteenth Lenormand card, representing structure, bureaucracy, stability and loneliness.
- To be very tall.
- To be high or lofty; to soar.
- To soar into.
- One who tows.