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kapow; bang; slap; clap
bulging; filled to bursting
prostitute (catering to Occupation soldiers in Japan after WWII)
風船がぱんぱんに膨らんだ。
The balloon inflated fully.
ぱんぱんと手を叩いて合図した。
I clapped my hands to signal.
靴がぱんぱんで足が痛い。
My shoes are tight and my feet hurt.