Answer: inseparable

AnswerCrossword Clue
INSEPARABLESome friends.
INSEPARABLEAlways together
inseparableUnable to be separated or treated separately
inseparable(of one or more people) Unwilling to be separated; usually seen together
inseparable(of a prefix) Not used as a separate word or (in German) not separated from the base verb when inflected
inseparablethat cannot be separated also UNSEPARABLE / something that cannot be separated