My mothers maiden name is Antrobus, and about 15 miles from where I was brought up is a small village called Antrobus ( North West of England in Cheshire ) - this I think is the probable origin of the name Antrobus.
Here is a links to it on a map -( if it doesn't work, go to multimap.com and search antrobus )
http://uk8.multimap.com/map/browse.cgi?place=Antrobus%2C+Che...There is also a myth in our family that the name comes from Herod Antipas, the famous Herod who lived at the same time of Jesus.