The most common and most likely answer to this crossword clue is the 7 letter word GATEWAY
I've seen this crossword clue in The Times
G
A
T
E
W
A
Y
Buddy explains!

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 GATEWAY mean?
GATEWAY noun- An entrance capable of being blocked by use of a gate.
- Any point that represents the beginning of a transition from one place or phase to another.
- A point at which freight moving from one territory to another is interchanged between transportation lines.
- (digital communications) In wireless internet, an access point with additional software capabilities such as providing NAT and DHCP, which may also provide VPN support, roaming, firewalls, various levels of security, etc.
- (digital communications) To make available via a gateway, or access point.