conjunction
not (that), but rather; without
Used to negate a preceding noun or nominalized clause and introduce an alternative. Often appears in the pattern AではなくB or AではなくてB, meaning 'not A but B'. The form ではなしに is a slightly more colloquial or emphatic variant of ではなく.
彼は医者ではなしに、教師です。
He is not a doctor but a teacher.
急ぐのではなしに、ゆっくりやろう。
Let's not rush, but take our time.