The most common and most likely answer to this crossword clue is the 7 plus 5 letter word STREETS AHEAD
I've seen this crossword clue in The Daily Telegraph
S
T
R
E
E
T
S
A
H
E
A
D
More clues leading to the result STREETS AHEAD
- Ways a teacher is far superior
- Unorthodox setters, each vastly superior
- Wasted head start? See superior
- Reversing undue speed in branch arrangement breaking down is much better
- Superior satnav shows these
- Greatly superior ways associated with a school principal
- Ways in front will be immeasurably better
- Far better than other door-to-door salesmen?
- About time pilots returning, each a long way off
- Far superior ways associated with a school principal
Buddy explains!
The straight part
We know that "immeasurably better" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case immeasurably better = streets ahead.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.