The most common and most likely answer to this crossword clue is the 2 plus 5 letter word ED ASNER
I've seen this crossword clue in Financial Times
E
D
A
S
N
E
R
More clues leading to the result ED ASNER
Buddy explains!
The straight part
We know that "Lou Grant" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lou grant = ed asner.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.