The most common and most likely answer to this crossword clue is the 8 letter word HEADLONG
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More clues leading to the result HEADLONG
- Principal wish is not considered
- Spread out, following teacher precipitately
- Leader has ache, at full speed
- Train had gone, carrying lost work by 3 at full speed
- To pine after teacher, maybe, is rash
- Rash on leg had developed
- Reckless leader to be dying
- Chief left on first stroke of gong in great haste
- Man and daughter entering together in haste
- Man, most lonely, accepts date with girl hurriedly
Buddy explains!

The straight part
We know that "in haste" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in haste = headlong.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 HEADLONG mean?
HEADLONG verb- To precipitate.
- Precipitous.
- Plunging downwards head foremost.
- Rushing forward without restraint.
- Reckless, impetuous.
- With the head first or down.
- With an unrestrained forward motion.
- Rashly; precipitately; without deliberation, in haste, hastily