ETYM Latin superfluus overflowing; super over, above + fluere to flow. Related to Super-, and Fluent.
More than is wanted or is sufficient; rendered unnecessary; useless; excessive.

1. That which remains when use or need is satisfied, or when a limit is reached; excess; overplus.
2. Specifically, a extra amount in finances, beyond what is budgeted

1. Not essential; not of prime importance; not indispensable; unimportant.
2. Void of essence, or real being.