The most common and most likely answer to this crossword clue is the 4 letter word ALEC
I've seen this crossword clue in The Times
A
L
E
C
More clues leading to the result ALEC
- Fellow caught with intoxicating liquor
- Guinness maybe cold after beer
- Porter, say, primarily consuming Guinness?
- Fellow divorce laws repelled, partly
- Guinness, say, something served in pubs cold
- Charlie on the beer gets one Guinness
- Conservative on the beer – smart man?
- Cold beer first — one Guinness so handled
- Smart boy that in France heads west
- Man in female costume
Buddy explains!

The straight part
We know that "Guinness" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case guinness = alec.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 ALEC mean?
ALEC noun- An anchovy or herring, especially pickled or dried.
- A sauce made from alecs; alec sauce.