There is not a way to lock down an account.  You may submit an enhancement request from Sage Desktop, Submit Product Idea.  If someone has already suggested this idea, you can vote for their idea. 

Our work-around is to redo the description as OLD *** Expense.  Sometimes it helps.  Also, from time to time we do delete accounts from the working data file if there are no amounts showing on the account's setup tabs.  This works for us because we archive our general ledger every single year so the accounts continue to exist in the older company folders we have made.