The district and MRT station name Ang Mo Kio stems from Hokkien. It’s written as 宏茂桥 (hóngmàoqiáo in Mandarin). As most Westerners in Singapore will know, a common way to refer to Caucasians is “Ang Mo”, a Hokkien term that is written as 红毛 (hóngmáo in Mandarin), hóng/Ang meaning ‘red’ and máo/mo meaning ‘hair’ – for some reason Caucasians have the reputation of having red hair. 桥 (qiáo / kio) means ‘bridge’.

Some Caucasians don’t like to be called ‘Ang Mo’. Personally I don’t mind and I don’t think it is always derogatory, but it can be. Hence the writing was changed to 宏茂桥 (hóngmàoqiáo – bridge of expansiveness and prosperity).
In actual fact, the name ‘Ang Mo’ in this case does not refer to a Westerner but to rambutans which is written exactly the same way (红毛). The rambutan is a local fruit that has a red surface and is covered by hair. It looks like the picture next to this text.
So the name of Ang Mo Kio litterally means “bridge where there are rambutans”, as it was indicated on old maps in the time that there were only kampungs (villages) in the area.