The most common and most likely answer to this crossword clue is the 4 letter word WALL
W
A
L
L
More clues leading to the result WALL
- With everything needed to create barrier
- First character in London street turned over barrier
- Rule about large barrier
- Part of building with everything?
- Lehman Brothers went to this wealthy Manhattan street
- Fool shortened property boundary
- Barrier hit after leaving work
- Snout’s part in a line of defence?
- Monied Manhattan street with everything?
- Surround women with everything
Buddy explains!

The straight part
We know that "blockade, perhaps" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case blockade, perhaps = wall.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 WALL mean?
WALL noun- A rampart of earth, stones etc. built up for defensive purposes.
- A structure built for defense surrounding a city, castle etc.
- Each of the substantial structures acting either as the exterior of or divisions within a structure.
- A point of desperation.
- A point of defeat or extinction.
- An impediment to free movement.
- A type of butterfly (Lasiommata megera).
- (often in combination) A barrier.
- A barrier to vision.
- Something with the apparent solidity and dimensions of a building wall.
- A divisive or containing structure in an organ or cavity.
- (auction) A fictional bidder used to increase the price at an auction.
- A doctor who tries to admit as few patients as possible.
- A line of defenders set up between an opposing free-kick taker and the goal.
- A personal notice board listing messages of interest to a particular user.
- To enclose with, or as if with, a wall or walls.
- To boil.
- To well, as water; spring.
- A spring of water.
- A kind of knot often used at the end of a rope; a wall knot or wale.
- To make a wall knot on the end of (a rope).
- Used to acknowledge a statement or situation.
- An exclamation of surprise (often doubled or tripled).
- An exclamation of indignance.
- Used in speech to express the overcoming of reluctance to say something.
- Used in speech to fill gaps, particularly at the beginning of a response to a question; filled pause.
- (Hiberno-English) Used as a greeting