Anonymous or anonymous describes someone whose name or identity is unknown --
The information was provided by an anonymous caller.
The scandalous book by an anonymous author caused a sensation in Washington.
Unanimous or unanimous describes a group in complete agreement, everyone having the same opinion --
The verdict was unanimous; everyone voted to convict.
We would like to discuss this until we reach a unanimous conclusion, but there isn't time.
Now that you know that, you can say --
"The decision of the board was unanimous; the new investor remained anonymous."
