cheatyoudaoicibaDictYouDict[cheat 词源字典]
cheat: [14] Cheat is a reduced form of escheat, a legal term for the reversion of property to the state on the death of the owner without heirs. This came from Old French escheoite, a derivative of the past participle of the verb escheoir ‘befall by chance, happen, devolve’, from Vulgar Latin *excadēre ‘fall away’, a compound verb formed from the prefix ex- ‘out’ and Latin cadere ‘fall’ (source of a wide range of English words from case ‘circumstance’ to occasion).

The semantic steps leading to the modern English sense of cheat seem to be ‘confiscate’; ‘deprive of something dishonestly’; ‘deceive’.
=> cadence, case, escheat, occasion, occident[cheat etymology, cheat origin, 英语词源]
cheat (v.)youdaoicibaDictYouDict
mid-15c., "to escheat," a shortening of Old French escheat, legal term for revision of property to the state when the owner dies without heirs, literally "that which falls to one," past participle of escheoir "happen, befall, occur, take place; fall due; lapse (legally)," from Late Latin *excadere "fall away, fall out," from Latin ex- "out" (see ex-) + cadere "to fall" (see case (n.1)). Also compare escheat. The royal officers evidently had a low reputation. Meaning evolved through "confiscate" (mid-15c.) to "deprive unfairly" (1580s). To cheat on (someone) "be sexually unfaithful" first recorded 1934. Related: Cheated; cheating.
cheat (n.)youdaoicibaDictYouDict
late 14c., "forfeited property," from cheat (v.). Meaning "a deceptive act" is from 1640s; earlier, in thieves' jargon, it meant "a stolen thing" (late 16c.), and earlier still "dice" (1530s). Meaning "a swindler" is from 1660s.