This is NOT what Daddy Snow says in his hit song "Informer". He says "a licky boom-boom dem" (not "down"), which means that the informers are ass-kissers. Any Jamaican knows this. "
Licky boom boom down" has no meaning, and it's not what Snow is saying either. It's just a mis-heard lyric by people who don't
understand Jamaican Patois. a "licky boom boom" is an ass-licker or ass-kisser. The "dem" at the end refers to "them", the informers. They are ass-kissers.