This dictionary term meaning "old" is applied to words like "wast"
... to 
become gradually consumed, used up, or worn away: .... Middle English < Old 
North French wast (Old French g (u) ast) < Latin vstus desolate; (v.) ... Synonym 
Study [DOC] [TLE] Wast | Define Wast at Dictionary.com [PAR] Wast definition, a 2nd person singular pt.