JMdict: 1011540

ペコペコ

1. [adj-na] very hungry; starving; famished
2. [adv,vs] bowing repeatedly; kowtowing; bowing and scraping; being obsequious; being servile
3. [adv,adv-to,vs,adj-na] denting; buckling; giving (in)

Words often seen with this one: (experimental feature)

お腹 (26), おなか (24), もう (15)