obligate

Etymology

It is borrowed from Latin obligātus (“bound, obliged”), the past participle of obligō (“to bind, bind up; to put under obligation”),^[2][3][4][5] which is formed from ob- (“to, towards”) and ligō (“to bind”),^[3] the source also of oblige.^[6][7] The adjective came first, in late Middle English, as obligat;^[3][5][8][9] the verb, from 1533, is from the Latin past participial stem, and the OED compares it with the earlier adjective.^[2][10] Etymonline and Barnhart also allow that the verb may be a back-formation from obligation.^[4][3] The biological sense of the adjective follows German obligat, apparently first used in 1884.^[2]

Earliest recorded meaning

As an adjective, bound by oath, law or duty, obliged: first in a translation of Higden's Polychronicon, dated by the OED to before about 1475 (composed perhaps before 1425),^[2][3] and by Merriam-Webster Unabridged to the 15th century.^[5] The verb is first recorded in 1533, in a letter in the Lisle Papers, meaning to bind a person morally.^[2][5]

Semantic evolution

The adjective "bound, obliged" was obsolete by the mid 17th century (last record 1663).^[2][10] Of the verb's early senses, "to pledge or mortgage a thing as security" (from 1541) lasted until the late 19th century,^[2][3] and the literal "to bind, fasten" (1547, and about 1600 in Timon) soon died out;^[2][4] the sense "to bind legally" is recorded from 1581.^[2] Etymonline dates the main modern sense, to put under a moral obligation, to the 1660s,^[4] though the OED has it from 1533.^[2] Johnson (1755) defined the verb as "to bind by contract or duty".^[11] From 1697 obligate could also mean to make someone indebted for a favour, the sense of oblige, with which Etymonline says it has been confused since the late 17th century; the OED marks both "bind morally" and "make indebted" as now chiefly American.^[4][2] The adjective was revived in 1887 in biology, after German, for an organism restricted to one mode of life, as an obligate parasite;^[2][9] the noun, an obligate organism, follows in 1907.^[2] In dialect the verb was widely used in Scotland, Ireland, England and America for "to oblige", especially in the passive.^[12]

Timeline

• 15th century – adjective, bound by oath, law or duty (obsolete after 1663).^[2][5]
• 1533 – verb, to bind a person morally; to compel, oblige.^[2][5]
• 1541 – to pledge a thing as security (obsolete after 1890).^[2][3]
• 1547 – to bind, connect, attach (obsolete).^[2]
• 1581 – to bind a person legally.^[2]
• 1697 – to make indebted by a favour.^[2]
• 1887 – adjective, in biology, restricted to one mode of life.^[2]
• 1907 – noun, in biology, an obligate organism.^[2]

Meanings

Verb

1. To bind or compel someone by a legal, moral or social duty: The contract obligates the builder to finish by June.^[6][5][13]
2. To commit funds to meet a particular obligation.^[6][5]
3. To make someone grateful or indebted; to oblige.^[6][5][2]
4. (chiefly US) To bind property or funds as security.^[13][5]
5. (obsolete) To bind or fasten.^[5][2]

Adjective

1. (biology) Able to live only under one set of conditions or in one way, as an obligate parasite that cannot survive without its host.^{[13][6][5][2]}
2. Unavoidable; necessary.^[5]
3. (obsolete) Bound by an obligation; obliged.^[5][2]

Word family

• obligable
• obligately
• obligator
• obligation
• obligatory

Related words

• oblige
• obligee
• obligor
• ligament
• ligature
• ligate

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b c d e f g h i j k l m n Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c d e The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
7. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
8. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
9. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
10. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
11. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
12. ^ Wright, Joseph, ed. (1898–1905), The English Dialect Dictionary, 6 vols., Oxford: Henry Frowde; via EDD Online 4.0, University of Innsbruck (CC BY 4.0)
13. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins