The most common and most likely answer to this crossword clue is the 4 letter word VENT
I've seen this crossword clue in The Times
V
E
N
T
More clues leading to the result VENT
- Opening race perhaps fails to start
- Opening contest shunned by beginner
- Opening found in Coventry
- Screen around November 26?
- Opening item in programme not started
- Put nitrogen in to check gas exhaust
- Express coming, with no announcement
- Opening of medical facility near the centre of Malvern
- Adventurer provides a means of escape
- Release issued from the Royal Opera House?
Buddy explains!

The straight part
We know that "Express" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case express = vent.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 VENT mean?
VENT noun- An opening through which gases, especially air, can pass.
- A small aperture.
- The opening of a volcano from which lava flows.
- A verbalized frustration.
- The excretory opening of lower orders of vertebrates.
- A slit in the seam of a garment.
- The opening at the breech of a firearm, through which fire is communicated to the powder of the charge; touchhole.
- In steam boilers, a sectional area of the passage for gases divided by the length of the same passage in feet.
- Opportunity of escape or passage from confinement or privacy; outlet.
- Emission; escape; passage to notice or expression; publication; utterance.
- To allow gases to escape.
- To allow to escape through a vent.
- To express a strong emotion.
- To snuff; to breathe or puff out; to snort.
- Ventriloquism.
- Sale; opportunity to sell; market
- To sell; to vend.
- A baiting place; an inn.
- Ventilation or ventilator.
- To ventilate; to use a ventilator; to use ventilation.