Green’s Dictionary of Slang

1. well-built.

1906

S. Ford Shorty McCabe 193: I reckon the Baron hadn’t any idea I’d strip as bunchy as I do.

2. chubby.

1914		N.Y. Tribune 22 Nov. 4/3: She’s a bunchy blond, she is, about four foot six in her French heels.
1931		D. Runyon ‘The Brain Goes Home’ in Runyon on Broadway (1954) 223: He is commencing to get a little bunchy about the middle.