string[] arrayWord = temp.Split(new char[] { 'u2295' }, StringSplitOptions.RemoveEmptyEntries);
var result = arrayWord.Distinct();

string[] source = new [] {
    "asdf",
    "asdf1",
    "asdf",
    "123",
    "1234",
    "123",
    "123",
};

// Для наглядности чего сколько
source.GroupBy(x => x).Select(x => new { Value = x.Key, Count = x.Count() }).Dump();

var result = source.GroupBy(x => x).Select(x => x.Key);
result.Dump();