Déphasé literally means 'out of phase' or 'out of sync'. It's a more nuanced word than simply 'confused' or 'lost', suggesting a disconnection from reality or a general state of being out of step with the world.
In the song, it's used to describe someone who is disoriented and not quite aligned with what's happening around them, fitting the overall theme of a character who is struggling and a bit lost in life. It's a great word to learn for expressing a feeling of being disconnected or out of touch.
Fais les Backs is a tongue-in-cheek portrait of the ultimate procrastinator. OrelSan and Gringe fire off a long list of everyday fails: dodging train tickets, living on triangle sandwiches, ignoring bank letters, and hitting snooze until the last possible second. Line after line, they tease a character who keeps saying he will do “great things” once he figures out what those things are, yet meanwhile drifts through life in a haze of cheap thrills, paranoia, and half-hearted excuses.
The repeated cry “Fais les backs” ("do the backing vocals") works like a friendly slap. It tells the listener, If you recognize yourself in this mess, stay in the background and just hype the chorus until you finally level up. Behind the humor lies a sharp social commentary on underachievement and self-sabotage, wrapped in catchy beats that make you want to turn up the volume even while you laugh at the bitter truth.