diff --git a/packages/db/src/db/schema.ts b/packages/db/src/db/schema.ts
index 4eb8473..e07e231 100644
--- a/packages/db/src/db/schema.ts
+++ b/packages/db/src/db/schema.ts
@@ -21,6 +21,7 @@ import {
   CEFR_LEVELS,
   DIFFICULTY_LEVELS,
   LOBBY_STATUSES,
+  NOUN_GENDERS,
 } from "@lila/shared";
 
 // ── Vocabulary ────────────────────────────────────────────────────────────────
@@ -112,6 +113,95 @@ export const entry_translations = pgTable(
   ],
 );
 
+export const words = pgTable(
+  "words",
+  {
+    id: uuid().primaryKey().defaultRandom(),
+    headword: text().notNull(),
+    language_code: varchar({ length: 10 }).notNull(),
+    pos: varchar({ length: 20 }).notNull(),
+    created_at: timestamp({ withTimezone: true }).defaultNow().notNull(),
+  },
+  (table) => [
+    unique("unique_word_per_language_and_pos").on(
+      table.headword,
+      table.language_code,
+      table.pos,
+    ),
+    check(
+      "words_language_code_check",
+      sql`${table.language_code} IN (${sql.raw(SUPPORTED_LANGUAGE_CODES.map((code) => `'${code}'`).join(", "))})`,
+    ),
+    check(
+      "words_pos_check",
+      sql`${table.pos} IN (${sql.raw(SUPPORTED_POS.map((pos) => `'${pos}'`).join(", "))})`,
+    ),
+    index("idx_language_code_pos").on(table.language_code, table.pos),
+  ],
+);
+
+export const senses = pgTable(
+  "senses",
+  {
+    id: uuid().primaryKey().defaultRandom(),
+    word_id: uuid()
+      .notNull()
+      .references(() => words.id, { onDelete: "cascade" }),
+    sense_index: smallint().default(0).notNull(),
+    difficulty: varchar({ length: 20 }).notNull(),
+    definitions: text().array().notNull().default([]),
+    examples: text().array().notNull().default([]),
+    created_at: timestamp({ withTimezone: true }).defaultNow().notNull(),
+  },
+  (table) => [
+    unique("unique_sense_per_word").on(table.word_id, table.sense_index),
+    check(
+      "senses_difficulty_check",
+      sql`${table.difficulty} IN (${sql.raw(DIFFICULTY_LEVELS.map((lvl) => `'${lvl}'`).join(", "))})`,
+    ),
+    index("idx_word_sense_difficulty").on(table.word_id, table.difficulty),
+  ],
+);
+
+export const translations = pgTable(
+  "translations",
+  {
+    id: uuid().primaryKey().defaultRandom(),
+    sense_id: uuid()
+      .notNull()
+      .references(() => senses.id, { onDelete: "cascade" }),
+    target_language_code: varchar({ length: 10 }).notNull(),
+    translation: text().notNull(),
+    gender: varchar({ length: 20 }),
+    difficulty: varchar({ length: 20 }).notNull(),
+    created_at: timestamp({ withTimezone: true }).defaultNow().notNull(),
+  },
+  (table) => [
+    unique("unique_translation_per_sense").on(
+      table.sense_id,
+      table.target_language_code,
+      table.translation,
+    ),
+    check(
+      "translations_language_code_check",
+      sql`${table.target_language_code} IN (${sql.raw(SUPPORTED_LANGUAGE_CODES.map((code) => `'${code}'`).join(", "))})`,
+    ),
+    check(
+      "translations_difficulty_check",
+      sql`${table.difficulty} IN (${sql.raw(DIFFICULTY_LEVELS.map((lvl) => `'${lvl}'`).join(", "))})`,
+    ),
+    check(
+      "translations_gender_check",
+      sql`${table.gender} IS NULL OR ${table.gender} IN (${sql.raw(NOUN_GENDERS.map((gender) => `'${gender}'`).join(", "))})`,
+    ),
+    index("idx_translations_sense_language_difficulty").on(
+      table.sense_id,
+      table.target_language_code,
+      table.difficulty,
+    ),
+  ],
+);
+
 // ── Auth (managed by Better Auth) ─────────────────────────────────────────────
 
 export const user = pgTable("user", {
@@ -243,6 +333,22 @@ export const entryTranslationRelations = relations(
   }),
 );
 
+export const wordRelations = relations(words, ({ many }) => ({
+  senses: many(senses),
+}));
+
+export const senseRelations = relations(senses, ({ one, many }) => ({
+  word: one(words, { fields: [senses.word_id], references: [words.id] }),
+  translations: many(translations),
+}));
+
+export const translationRelations = relations(translations, ({ one }) => ({
+  sense: one(senses, {
+    fields: [translations.sense_id],
+    references: [senses.id],
+  }),
+}));
+
 export const userRelations = relations(user, ({ many }) => ({
   sessions: many(session),
   accounts: many(account),