compatriot n.

word-forming element usually meaning "with, together," from Latin com, archaic form of classical Latin cum "together, together with, in combination," from PIE *kom- "beside, near, by, with" (compare Old English ge-, German ge-). The prefix in Latin sometimes was used as an intensive.

Before vowels and aspirates, it is reduced to co-; before -g-, it is assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, and -v-, it is assimilated to con-, which was so frequent that it often was used as the normal form.

1590s, "compatriot," from French patriote (15c.) and directly from Late Latin patriota "fellow-countryman" (6c.), from Greek patriotes "fellow countryman," from patrios "of one's fathers," patris "fatherland," from pater (genitive patros) "father" (see father (n.)); with -otes, suffix expressing state or condition. Liddell & Scott write that patriotes was "applied to barbarians who had only a common [patris], [politai] being used of Greeks who had a common [polis] (or free-state)."

Meaning "loyal and disinterested lover and defender of one's country and its interests" is attested from c. 1600, but it became an ironic term of ridicule or abuse from mid-18c. in England, so that Johnson, who at first defined it as "one whose ruling passion is the love of his country," in his fourth edition added, "It is sometimes used for a factious disturber of the government."

The name of patriot had become [c. 1744] a by-word of derision. Horace Walpole scarcely exaggerated when he said that ... the most popular declaration which a candidate could make on the hustings was that he had never been and never would be a patriot. [Macaulay, "Horace Walpole," 1833]

It was somewhat revived in reference to resistance movements in overrun countries in World War II, and it has usually had a positive sense in American English, where the phony and rascally variety has been consigned to the word patrioteer (1928).

Oriana Fallaci ["The Rage and the Pride," 2002] marvels that Americans, so fond of patriotic, patriot, and patriotism, lack the root noun and are content to express the idea of patria by cumbersome compounds such as homeland. (Joyce, Shaw, and H.G. Wells all used patria as an English word early 20c., but it failed to stick.) Patriots' Day (April 19, the anniversary of the 1775 skirmishes at Lexington and Concord Bridge) was observed as a legal holiday in Maine and Massachusetts from 1894.