I. noun see: full
Date: 13th century
1. a full or more than adequate amount or supply , a large number or amount , the quality or state of being copious ; plentifulness,
II. adjective
Date: 14th century
plentiful in amount, number, or supply , ample ,
Usage: Many commentators object to use of sense 2 in writing; it appears to be limited chiefly to spoken English. Sense 1 is literary but is no longer in common use.
III. adverb
Date: 1842
more than sufficiently ; to a considerable degree ,
Usage: Many handbooks advise avoiding the adverb plenty in writing; “use very, quite, or a more precise word,” they advise. Actually plenty is often a more precise word than its recommended replacements; very, fully, or quite will not work as well in these typical quotations