Can I say these? Which is to be preferred? or have you got any other suggestion?

> 
> Hereinafter client refers to a smartphone using Android.
> 
> 
> Henceforward client refers to a smartphone using Android.
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> 
> 

My intended meaning is that when I say "client" I mean an Android smartphone.

Earlier in the text I describe different kinds of possible clients, but since my report only focuses on android phones I want to be able to write "client" and have the reader understand the meaning of 'client' as 'Android phone'.