doo-wop {It was sung in Rocky Balboa's neighborhood}. Doo-wop features in several movies in the Rocky series , e.g. as sung by Frank Stallone , Sylvester 's brother. 19a epi- {Center opening?}. Reference to epi- as a prefix in  epicenter. 22a DST {Forward-moving occasion?: Abbr.}. DST = Daylight saving time ,