牛仔/牛佬/鬼佬 Cow boy / Cow man/ Ghost

Today,my Portuguese colleague asked us -
what were the meaning of  "cow boy/cow man" 牛仔/牛佬,
and what was the difference.

At the beginning,
we were very surprised,
for a Portuguese who didn't speak Chinese,
he was interested of these two terms.

After the explanation,
he explained that outside the office,
for many times,
he heard the people called him "cow man" !
He caught the pronunciation,
and was curious about the exact meaning.

Yes,
it reminded me that in the old time,
we, the Chinese called the western people as cow boy,
and also -
ghost 鬼佬,
for they look very different with our Chinese.

Got this information from wiki:

「鬼佬」除了表示白人外，也常特指白種男人。
 粵語俗話中亦有不少類似的稱呼：

• 如稱呼白種女人：鬼婆
• 如稱呼白種男孩：鬼仔
• 如稱呼白種年輕女孩：鬼妹
• 如稱呼黑人：黑鬼
• 如稱呼黑人女性：黑鬼婆

當中「黑鬼」和「黑鬼婆」帶有一定侮辱性。