underpay v.

Old English under (prep.) "beneath, among, before, in the presence of, in subjection to, under the rule of, by means of," also, as an adverb, "beneath, below, underneath," expressing position with reference to that which is above, from Proto-Germanic *under- (source also of Old Frisian under, Dutch onder, Old High German untar, German unter, Old Norse undir, Gothic undar), from PIE *ndher- "under" (source also of Sanskrit adhah "below;" Avestan athara- "lower;" Latin infernus "lower," infra "below").

Productive as a prefix in Old English, as in German and Scandinavian (often forming words modeled on Latin ones in sub-). Notion of "inferior in rank, position, etc." was present in Old English. With reference to standards, "less than in age, price, value," etc., late 14c. As an adjective, "lower in position; lower in rank or degree" from 13c. Also used in Old English as a preposition meaning "between, among," as still in under these circumstances, etc. (though this may be an entirely separate root; see understand).

Under the weather "indisposed" is from 1810. Under the table is from 1913 in the sense of "very drunk," 1940s in sense of "illegal" (under-board "dishonest" is from c. 1600). To keep something under (one's) hat "secret" is from 1885; to have something under (one's) nose "in plain sight" is from 1540s; to speak under (one's) breath "in a low voice" is attested from 1832.

c. 1200, paien, "to appease, pacify, satisfy, be to the liking of," from Old French paier "to pay, pay up" (12c., Modern French payer), from Latin pacare "to please, pacify, satisfy" (in Medieval Latin especially "satisfy a creditor"), literally "make peaceful," from pax (genitive pacis) "peace" (see peace).

The meaning "to give what is due for goods or services" arose in Medieval Latin and was attested in English by early 13c.; the sense of "please, pacify" died out in English by 1500. Figurative sense of "suffer, endure" (a punishment, etc.) is first recorded late 14c. Meaning "to give or render" with little or no sense of obligation (pay attention, pay respects, pay a compliment) is by 1580s. Meaning "be remunerative, be profitable, yield a suitable return or reward" is by 1812. Related: Paid; paying. To pay up was originally (mid-15c.) "make up the difference between two sums of money;" the sense of "pay fully or promptly" is by 1911. Pay television is attested by 1957.