The most common and most likely answer to this crossword clue is the 7 letter word GLIBBER
G
L
I
B
B
E
R
Buddy explains!

The straight part
We know that "is more slick" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case is more slick = glibber.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 GLIBBER mean?
GLIBBER adjective- Having a ready flow of words but lacking thought or understanding; superficial; shallow.
- Smooth or slippery.
- Artfully persuasive but insincere in nature; smooth-talking, honey-tongued, silver-tongued.