Salgadinho (or simply salgado - "salty") englobes snacks , such as pastel,esfiha bolinha de queijo, empada (also called empadinha), risoles, quibe, enrolado, croquete, pão de batata, etc.
It's usually some type of dough and meat or other filling fried in hot oil and, in general, are very cheap. An example of what could be called a salgado or salgadinho here in Brazil, are the American/Kiwi/etc pies, like mince & cheese pies.
- Que cê vai comer?
- Tô quebrado, vou ter que comer um salgado com coca só.
It can refer to a) a Mango Tree (mangueira in Portuguese, or pé de manga too), b) to the famous carioca Samba School, Estação Primeira de Mangueira (aka Mangueira), or yet to c) a hose. It really depends on the context.
- Você vai na mangueira hoje a noite? (probably the samba school, since not a lot of people go to mango trees at night... I believe; and since a hose here wouldn't make any sense)
- Eu estava há duas semanas limpo, mas ontem tive uma recaída...
Aeroporto de mosquitos ("mosquitoes airport") is a diminutive way of addressing a bald man.
- Ei aeroporto de mosquito! Lembrou de usar shampoo?