The most common and most likely answer to this crossword clue is the 7 letter word WEEDIER
I've seen this crossword clue in The Daily Telegraph
W
E
E
D
I
E
R
Buddy explains!
The straight part
We know that "More frail" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case more frail = weedier.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 WEEDIER mean?
WEEDIER adjective- Abounding with weeds.
- Of, relating to or resembling weeds.
- Consisting of weeds.
- Characteristic of a plant that grows rapidly and spreads invasively, and which grows opportunistically in cracks of sidewalks and disturbed areas.
- (of a person or animal) Small and weak.
- Lacking power or effectiveness.