One who favors seclusion, or the principle or policy of refusing intercourse with others: as, Chinese seclusionists; monkish seclusionists.(noun)
The Century Dictionary (Public Domain)
Use "seclusionist" in a sentence
"So would that make me some right wing, seclusionist nutjob whose only ideal it is to isolate my children and family from the evils of public school?"
"These partys are normaly most popular in a seclusionist government and are opposed by them in every way."
"This group is headed by the Botswana Unity Party, Political partys in this group tend to belive in a middle line between the seclusionist and Expansionist viewpoints."