muchacha have two meanings, in the first case, the usual, muchacha is "girl", but the second case is when you call a maid, in latin america the maids are not like english maids, usually the "muchachas" or simply "chachas" were girls without education and future in the life, her only purpose were to serve to the landlord and usually the chachas were dirty and didn´t talk spanish very well, and they were like slaves along time ago (XIX century), in some countries the muchacha (maid) is still running, but now is usually to talk muchacha just like a girl.

No, just as Mary said muchacha is not an offensive word, it can be used to refer to a young girl. Some people also use it when talking to someone else about the girl they hired to help them with cleaning or housework in general maybe that's why maid was in the dictionary

In my country means two things or maybe more, but i know muchacha is a girl or muchacha is who makes the housekeeping, but it is not an insult.

Muchacha means young lady

deberia pasear un dia por colombia, usted podra escuchar "parcero, llaveria, parce, calidad, mocoso, pelao, luqueao, reluqueao, lachimba....etc.etc.etc