means Able to move or be moved freely, or — increasingly — the pocket-sized phone-computer we carry everywhere.

from From Latin 'mobilis,' meaning movable, itself worn down from 'movibilis' off the verb 'movere,' to move — the same root that gives us 'motion,' 'motive,' and 'momentum.' For centuries 'mobile' simply meant capable of movement; the 'mobile phone' sense is a 20th-century arrival, naming the device by the very thing that set it apart from the wired telephone bolted to your wall.