The most common and most likely answer to this crossword clue is the 7 letter word AIRPORT
I've seen this crossword clue in The Times
A
I
R
P
O
R
T
More clues leading to the result AIRPORT
- Look over alcohol where there are duty-free shops
- 6 ceding power left transport hub
- Charles de Gaulle, eg, left pressed by publicity
- Article Irish left in travel complex
- Perhaps JFK left after show
- Broadcast left for JFK, possibly?
- Bearing left for transport hub
- Couple, heading off, left transport hub
- Bearing left in Heathrow, say
- Move up from here
Buddy explains!

The straight part
We know that "Heathrow, say" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case heathrow, say = airport.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 AIRPORT mean?
AIRPORT noun- An airfield (an area designated for the takeoff and landing of aircraft), including one or more runways and (for commercial airports) one or more passenger terminals.