Well, this should be simple: nomos is the Greek for law, and phobia is another Greek word which denotes unreasonable fear or anxiety (note the unreasonable bit: you can't have a phobia about being in the water with a large crocodile. That's a fear. Unless it stops you going down to the local indoor swimming pool, natch.).
Anyway, nomophobia looks as if it should be an unreasonable fear of the law - but it's not. It's actually an unreasonable fear of being out of mobile phone contact.
Yes, the word was made up by people who care nothing for the classics.
Nomophobia tends to affect, especially, those under twenty and those over seventy. It tends to affect the depressed and the insecure, too.
Would these people, I wonder, have had a similar need for constant communication if phones hadn't been invented? I can't help but think that then their anxieties might have been harder to soothe; so perhaps we shouldn't be blaming the phones.
I don't know what the word is to describe someone who dislikes having a mobile phone signal (how on earth can anyone think with people jabbering away at you all the time?) but mostly I'm one of those.
Still, even I can work the off-switch, so I can't say it causes me any great problems.
Word To Consider Today: nomophobia. This word was coined by the UK Post Office in 2010. It's short for no-mobile-phone-contact-phobia. Ugh.