Origins
The English word 'digest' entered the language around 1384 from Latin 'dīgestus,' the past participle of 'dīgerere' (to separate, to distribute, to dissolve, to arrange systematically). The Latin verb combines the prefix 'dī-' or 'dis-' (apart, asunder) with 'gerere' (to carry, to bear, to manage, to conduct). The etymological meaning is to carry apart — to separate something into its constituent elements and arrange them.
This original sense of systematic arrangement is the oldest meaning of the word in both Latin and English. The most famous use is the 'Digesta' (Digest) of the Emperor Justinian, compiled in 533 CE — a massive systematic arrangement of Roman legal writings that became the foundation of civil law systems across continental Europe. The title 'Digesta' means 'things arranged,' 'things sorted' — the legal opinions of centuries of Roman jurists were carried apart, categorized, and reassembled into a coherent system. This sense of 'digest' as a compilation or summary persists in English: Reader's Digest, a law digest, a news digest — all are collections of material sorted and arranged for easier consumption.
The biological meaning — to break down food in the stomach and intestines — developed as a metaphorical extension of the arrangement sense. The stomach 'digests' food by separating it into its nutritive components, carrying it apart into substances the body can absorb. This application of the word to the body's processing of food is attested in English from the late fourteenth century, roughly contemporaneous with the arrangement sense. The two meanings coexisted from the start, united by the core idea of breaking something down into its parts.
Latin Roots
The intellectual meaning — to digest information, to absorb and think through complex material — is a further metaphorical layer. Just as the stomach breaks down food into usable nutrients, the mind breaks down information into usable understanding. This sense is attested from the sixteenth century and remains vigorous: 'I need time to digest this news' uses the same metaphor that was already well established in Latin.
The Latin root 'gerere' (to carry, to bear, to manage, to wage) is itself remarkably productive. It has given English 'gesture' (a carrying of the body), 'suggest' (to carry under, to hint), 'register' (to carry back, to record), 'belligerent' (waging war, from 'bellum gerere'), 'congestion' (carrying together, crowding), 'exaggerate' (to heap up, from 'ex-' + 'aggerāre,' related to 'gerere'), and 'ingest' (to carry in, the opposite of digest). The family is united by the idea of carrying, managing, and conducting — activities fundamental to both physical and intellectual life.
The noun 'digest' (with stress on the first syllable, unlike the verb) has maintained the Justinianic meaning across centuries. Legal digests, news digests, and literary digests all present material that has been sorted, summarized, and arranged for the reader's benefit. The shift in stress between noun and verb (DIgest versus diGEST) follows a common English pattern in Latinate words: compare PROduce / proDUCE, REcord / reCORD, OBject / obJECT.
Later History
The derivative 'digestion' entered English in the fourteenth century, 'digestive' in the fifteenth. A 'digestive biscuit,' a staple of British baking since the nineteenth century, was originally marketed with the claim that its high baking-soda content aided digestion — a claim that is nutritionally questionable but etymologically precise. In French, 'un digestif' refers to a drink taken after a meal to aid digestion, typically a brandy or liqueur. This usage has entered English as 'digestif.'
The word's triple life — as a term for biological processing, intellectual absorption, and systematic compilation — is a sign of the power of the underlying metaphor. Breaking things down into their parts is what stomachs do, what minds do, and what editors do. The Latin verb 'dīgerere' captured this abstract pattern with precision, and English has kept all three applications alive for over six centuries.