Depreciated is the past-tense form of depreciation, and describes a long-term asset whose cost has been partly or fully moved to expense over its useful life. When an accountant says a machine "has been depreciated by $30,000", it means $30,000 of its cost has been charged to depreciation expense in the periods so far.
What being depreciated means for the books
Each period's depreciation is recorded with a debit to Depreciation Expense and a credit to Accumulated Depreciation, a contra-asset account. The asset's original cost stays in its own account, so the balance sheet shows cost, the amount depreciated to date, and the difference, the carrying value.
Suppose a delivery van cost $40,000, has an estimated salvage value of $4,000 and a six-year life. Under the straight-line method it is depreciated by $6,000 a year. After four years it has been depreciated by $24,000, and its carrying value is $16,000.
An asset that has been depreciated down to its salvage value is described as fully depreciated. No further depreciation is recorded, even if the asset is still in use, and it stays on the books at cost less accumulated depreciation until it is sold or scrapped. "Depreciated" refers only to this cost allocation; it does not mean the asset's market value has fallen by the same amount.