Crawl, lazily, at first, beneath small plantation (6)
I believe the answer is:
grovel
'crawl' is the definition.
('grovel' can be a synonym of 'crawl')
'lazily at first beneath small plantation' is the wordplay.
'at first' indicates taking the first letters.
'beneath' says to put letters next to each other (in a down clue).
'small plantation' becomes 'grove' (I've seen this before).
The first letter of 'lazily' is 'l'.
'l' after 'grove' is 'GROVEL'.
(Other definitions for grovel that I've seen before include "Creep" , "Prostrate oneself" , "Behave obsequiously in fear or servitude" , "Show extreme humility" , "Crawl abjectly" .)