José Henrique Lamensdorf wrote:
A job - Yep, that's what I do for a living.
An art - Quite often, the art of concealing that something was not originally written in the language it is now.
A mission - When a professional decides to do it comme il faut, in spite of the pressure for low rates, impossible deadlines, often unjustified specific software (usually CAT tools), and indecisive clients who wait beyond reason before requesting the inevitable to be done, and then who pay only after the pressure on them has become unbearable.
A dream - When I get hired by clients who value my work.
A nightmare - When the source material is so bad that I wonder what's the point in translating it. Sometimes, when the source material is already a bad translation, and I am expected to salvage whatever I can from it, as quickly and as economically as I can.
A bore - When the original writer was paid like me - by the word - and was in a desperate need for cash, so they may have used, say, nine words to express what could be said in one, over and over again. Very common in business agreements.
It may also be a host of other things, a challenge, teamwork, a craft, a pleasure, etc.
For me it's all of the above except "nightmare", and I would add "passion"".