Clayton's Case Definition: An English case which established a presumption that monies withdrawn from a money account are presumed to be debits from those monies first deposited; first in, first out. Related Terms: First In, First Out Rule An 1816 English case which established a presumption that monies withdrawn from a money account are presumed to be debits from those monies first deposited; first in, first out.The proper citation is Devaynes v. Noble (aka Clayton's Case) 1 Mer. 572, also at 35 E.R. 781 (1816).The presumption is not applicable to fiduciaries, who are presumed to withdraw their own money first, and not trust money.REFERENCES:Duhaime, Lloyd, Legal Definition of First In, First Out Rule Find you are constantly looking up definitions? Try our search provider (works in most modern browsers) If you find an error or omission in Duhaime's Legal Dictionary, or if you have legal term suggestion, we'd love to hear from you!