Laki-laki = male (usually for boy, I think. Could be wrong though)
Laki = husband, man
I think the first word is laki-laki, then laki comes afterward. So the original word is laki-laki not laki. This is one of exception duplication words that is a singular word that you should remember. Also it's valid to say "laki-laki laki-laki itu" (those boys) btw lol.