late 14c., "possible" (as opposed to actual), "capable of being or becoming," from Old French potenciel and directly from Medieval Latin potentialis "potential," from Latin potentia "power, might, force;" figuratively "political power, authority, influence," from potens "powerful," from potis "powerful, able, capable; possible;" of persons, "better, preferable; chief, principal; strongest, foremost," from PIE root *poti- "powerful; lord."

The noun, meaning "that which is possible, anything that may be" is attested by 1817 (Coleridge), from the adjective. Middle English had potencies (plural) "a caustic medicine" (early 15c.).

mid-15c., potencialli, "in possibility, in an undeveloped or unrealized manner or state" (opposed to actually); from potential + -ly (2).

"capable of developing in any of various directions," 1925, from pluri- + potential. Related: Pluripotent; pluripotency.

"state of being potential, mere being without actualization," 1620s, from potential + -ity, or else from Medieval Latin potentialitas, from potentialis.

"instrument for measuring the difference of electrical potential between two points," 1868, a hybrid formed from combining form of Latin potentia "power" (see potential) + Greek-derived -meter. Related: Potentiometric.

Proto-Indo-European root meaning "powerful; lord." 

It forms all or part of: bashaw; compos mentis; despot; hospodar; host (n.1) "person who receives guests;" idempotent; impotent; omnipotent; pasha; plenipotentiary; posse; possess; possible; potence; potency; potent; potentate; potential; potentiate; potentiometer; power; totipotent. 

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit patih "master, husband;" Greek posis, Lithuanian patis "husband;" Latin potis "powerful, able, capable; possible." 

Italian immigrant secret society in U.S., 1904; earlier a Spanish anarchist society, both from the warning mark they displayed to potential victims.

"the making actual, by an exertion of will, that which lies dormant in one's soul; the fulfilment, by one's own effort, of the potential in one's soul," 1839, from self- + realization.

1966 in reference to an alternative philosophy and human potential movement, from Esalen Institute in Big Sur, California, U.S., from Esselen, name of an extinct Native American people of the California coast, for which Bright gives no etymology.

1833, "crowd;" 1858, "phony money," especially "graft money," actual or potential (1883), both American English slang, either or both based on bundle (n.), or from Dutch boedel "property, riches," which is from Proto-Germanic *bothla, from PIE root *bheue- "to be, exist, grow."