The adjective aloof means being not friendly or willing to take part in things.
Synonyms are remote, distant, detached, or haughty.
The word origins from a– meaning “on” plus Middle English loof meaning “windward direction”, probably from Dutch loef (Middle Dutch lof) meaning “the weather side of a ship”. In 1530s, its original sense in nautical orders to keep the ship’s head to the wind, thus to stay clear of a lee-shore or some other quarter; hence “at a distance but within view” and, figuratively, “apart, withdrawn, without community spirit”.
His aloof response puzzled her.
He kept himself aloof from the crazy crowd at the party.
The nation stood aloof in the middle of the global issue.