The most common and most likely answer to this crossword clue is the 6 letter word LENGTH
I've seen this crossword clue in Financial Times
L
E
N
G
T
H
More clues leading to the result LENGTH
- Section of latrine needing trough emptied
- Linear extent not getting the height, initially?
- Measure litres, then stupidly drinking gallons
- Advanced, gaining ground initially — hour’s duration
- Lacklustre, nauseating Telegraph, devoid of content or dimension
- The long version lacks nothing in measurement
- Hospital needed after surprisingly short, gentle stretch
- Duration of lunch a guest regularly cooked
- Extent to which outside line is no good to horses at the start
- New in cricket side, needing time before hard stretch
Buddy explains!

The straight part
We know that "measurement" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case measurement = length.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 LENGTH mean?
LENGTH noun- The distance measured along the longest dimension of an object.
- Duration.
- The length of a horse, used to indicate the distance between horses at the end of a race.
- Distance between the two ends of a line segment.
- The distance down the pitch that the ball bounces on its way to the batsman.
- Total extent.
- Part of something that is long; a physical piece of something.
- To lengthen.