Depends, we have generally 4 names
1 "night halt", if a layby carpark and it's crap but can't find owt else (... and probably won't go back for a 2nd time, nor recommend it as a POI).
2 "wild camping", if parked up on a beach or on a POI.
3 "cheeky campings", if parked where we shouldnae !
4 "aires" or "WC" generally anywhere in France.
I've proper wilded and rubbed sticks to keep warm (!) under the stars and tree branches but I still call it WC in the M/H and that's fine by me, because the distinction for us is NOT a campsite.
Whilst we're at it we freely interchange the words "Motorhome" & "Camper" depending upon the wind -> don't care, makes no odds.
Chrz Mul.