Definition of "dietary"

For example, the antitumour depsipeptide kahalalide F was isolated from the opisthobranch mollusc Elysia rufescens, and is used by both the mollusc and its dietary alga Bryopsis spp.

2016 January 21, “Choose Your Weaponry: Selective Storage of a Single Toxic Compound, Latrunculin A, by Closely Related Nudibranch Molluscs”, in PLOS ONE‎

“[…] Do I understand that he asked for more, after he had eaten the supper allotted by the dietary?” “He did, sir,” replied Bumble. “That boy will be hung,” said the gentleman in the white waistcoat; “I know that boy will be hung.” Nobody controverted the prophetic gentleman’s opinion.

1837 February, Boz [pseudonym; Charles Dickens], “Treats of Oliver Twist’s Growth, Education, and Board”, in Oliver Twist; or, The Parish Boy’s Progress. […], volume I, London: Richard Bentley, […], published 1838, page 30