The most common and most likely answer to this crossword clue is the 11 letter word CATERPILLAR
I've seen this crossword clue in The Guardian
C
A
T
E
R
P
I
L
L
A
R
More clues leading to the result CATERPILLAR
- Provide support in early stage of life
- Insect larva to provide food on tall upright rock
- Provide food and support for butterfly larva
- Provide food and drink support — grub you may not want to eat!
- Provide table for upright creature
- Maybe track flier eventually
- Supply post providing grub
- Provide food? I will, putting on standard grub
- Grub to provide food and support
- Trace lost post to find vehicle using tracks
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 CATERPILLAR mean?
CATERPILLAR noun- The larva of a butterfly or moth; leafworm.
- A vehicle with a caterpillar track; a crawler.