The most common and most likely answer to this crossword clue is the 6 letter word APOGEE
A
P
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E
More clues leading to the result APOGEE
- High point of a river: wow!
- Highest position of a Personnel Officer — that’s surprising!
- Highpoint of a sailor’s meeting with brother
- Culmination of attempt to pursue secretary brought about by drugs
- Highest point reached by river in a long time, end of June
- Highest point of a river – source of Ganges
- Work over? Jock’s hardly open about that as culmination
- In part, male ego panicked about height
- Ultimate height of a river that amazes me
- Top mimic capturing monster, right away
Buddy explains!

The straight part
We know that "height" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case height = apogee.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 APOGEE mean?
APOGEE noun- The point, in an orbit about the Earth, that is furthest from the Earth: the apoapsis of an Earth orbiter.
- (more generally) The point, in an orbit about any planet, that is farthest from the planet: the apoapsis of any satellite.
- (possibly obsolete outside astrology) The point, in any trajectory of an object in space, where it is furthest from the Earth.
- The highest point.