The most common and most likely answer to this crossword clue is the 5 letter word UPPER
I've seen this crossword clue in The Times
U
P
P
E
R
More clues leading to the result UPPER
- Drug found in meal, but not initially
- Superior meal, but no starter
- Not the sole promoter?
- Northern feast to which south not invited
- Superior meal with no starter
- In an excited state, having taken a stimulant
- Part of boot for hiker?
- Patient on stimulant, capital
- University pressure? A stimulant is the answer
- Meal without starter as stimulant
Buddy explains!

The straight part
We know that "Part of boot/ hiker" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case part of boot/ hiker = upper.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 UPPER mean?
UPPER noun- A stimulant, such as amphetamine, that increases energy and decreases appetite.
- The upper portion of something
- Someone with higher social standing
- That which is higher, contrasted with the lower.
- A spiritual passageway through which consciousness can reach a higher dimension.
- At a higher level, rank or position.
- Situated on higher ground, further inland, or more northerly.
- (of strata or geological time periods) younger, more recent
- Of or pertaining to a secondary school.