Here are the possible solutions for someone not mine or yours clue
Answer
Clue
Relevancy
elses
Clue
Someone ___ (not yours or mine)
Someone ___ (not mine or yours)
ours
Clue
Not yours or mine, yet both
Definition
belonging to us, also OURN
theirs
Clue
Not yours or mine
nontransferable
Clue
Yours and yours only
Definition
not transferable
reefermadness
Clue
1930s anti-marijuana propaganda film that ends with the principal of a school saying, "The next tragedy may be that of your daughter...or your son...or yours or yours..." [points at the camera] "... o