Huge fellows squeezed into semi, getting sozzled (7)
I believe the answer is:
immense
'huge' is the definition.
('immense' can be a synonym of 'huge')
'fellows squeezed into semi getting sozzled' is the wordplay.
'fellows' becomes 'men' (I've seen this before).
'squeezed into' indicates putting letters inside.
'getting sozzled' is an anagram indicator (sozzled can mean drunk and therefore disordered).
'semi' anagrammed gives 'imse'.
'men' inserted within 'imse' is 'IMMENSE'.
(Other definitions for immense that I've seen before include "'Gigantic, extensive (7)'" , "Unctuously ingratiating" , "Exceedingly large" , "Unusually great in size" , "Very big, really huge" .)