Brief attempt to get chubby (3)
I believe the answer is:
fat
'chubby' is the definition.
(similar in meaning)
'brief attempt to get' is the wordplay.
'to get' says the answer is hidden in the clue (I've seen 'got' mean this).
'FAT' can be found hidden inside 'brief attempt'.
(Other definitions for fat that I've seen before include "Obese, having spare tyre etc" , "Corpulent; little (chance)" , "and 24: Overpaid City type" , "eg Lard" , "Profitable" .)