its Look up its at Dictionary.com
neuter possessive pronoun; the modern word begins to appear in writing at the end of 16c., from it + genitive/possessive ending 's (q.v.), and "at first commonly written it's, a spelling retained by some to the beginning of the 19c." [OED]. The apostrophe came to be omitted, perhaps because it's already was established as a contraction of it is, or by general habit of omitting apostrophes in personal pronouns (hers, yours, theirs, etc.).

The neuter genitive pronoun in Middle English was his, but the clash between grammatical gender and sexual gender, or else the application of the word to both human and non-human subjects, evidently made users uncomfortable. Restriction of his to the masculine and avoidance of it as a neuter pronoun is evidenced in Middle English, and of it and thereof (as in KJV) were used for the neuter possessive. Also, from c.1300, simple it was used as a neuter possessive pronoun. But in literary use, his as a neuter pronoun continued into the 17c.
itself (pron.) Look up itself at Dictionary.com
late 14c., from Old English hit sylf, from it + self. Since 17c. usually regarded as its self (compare its own self).
itsy-bitsy (adj.) Look up itsy-bitsy at Dictionary.com
"charmingly small," 1890, from itty and/or bitsy. Bitsy-itsy is recorded from 1875.
benefits (n.) Look up benefits at Dictionary.com
"financial support (especially for medical expenses) to which one is entitled through employment or membership," 1895, plural of benefit (n.).
bitsy (adj.) Look up bitsy at Dictionary.com
1883, from plural of bit (n.1) or a variant of bitty.
grits (n.) Look up grits at Dictionary.com
plural of grit "coarsely ground grain," Old English grytt (plural grytta) "coarse meal, groats, grits," from Proto-Germanic *grutja-, from the same root as grit, the two words having influenced one another in sound development.

In American English, corn-based grits and hominy (q.v.) were used interchangeably in Colonial times. Later, hominy meant whole kernels that had been skinned but not ground, but in the U.S. South, hominy meant skinned kernels that could be ground coarsely to make grits. In New Orleans, whole kernels are big hominy and ground kernels little hominy.
jujitsu (n.) Look up jujitsu at Dictionary.com
also ju-jitsu, 1875, from Japanese jujutsu, from ju "softness, gentleness" (from Chinese jou "soft, gentle") + jutsu "art, science," from Chinese shu, shut.
kitsch (n.) Look up kitsch at Dictionary.com
1926, from German kitsch, literally "gaudy, trash," from dialectal kitschen "to smear."
What we English people call ugliness in German art is simply the furious reaction against what Germans call süsses Kitsch, the art of the picture postcard, and of what corresponds to the royalty ballad. It has for years been their constant reproach against us that England is the great country of Kitsch. Many years ago a German who loved England only too well said to me, 'I like your English word plain; it is a word for which we have no equivalent in German, because all German women are plain.' He might well have balanced it by saying that English has no equivalent for the word Kitsch. [Edward J. Dent, "The Music of Arnold Schönberg," "The Living Age," July 9, 1921]
kitschy (adj.) Look up kitschy at Dictionary.com
1965, from kitsch + -y (2). Related: Kitchiness.
off-limits (adj.) Look up off-limits at Dictionary.com
"forbidden," by 1881, U.S. military academies jargon, from off (adv.) + limit (n.). Earlier (1857) it was applied to cadets, etc., who were in violation of the limitations on their movement and behavior.
pits (n.) Look up pits at Dictionary.com
"the worst," by 1953, U.S. slang, said to be a shortened form of armpits.
quits (adj.) Look up quits at Dictionary.com
"even" (with another), 1660s; earlier "discharged of a liability" (c.1200), perhaps from Medieval Latin quittus (see quit (adj.)).
quoits (n.) Look up quoits at Dictionary.com
late 14c., coytes "game played by throwing quoits;" see quoit.
two bits (n.) Look up two bits at Dictionary.com
"quarter dollar," 1730, in reference to the Mexican real, a large coin that was divided into eight bits; see bit (n.1). Compare piece of eight (see piece (n.)). Two bits thus would have equaled a quarter of the coin. Hence two-bit (adj.) "cheap, tawdry," first recorded 1929.
waitstaff (n.) Look up waitstaff at Dictionary.com
1981, American English; see waiter + staff (n.).
Whitsun Look up Whitsun at Dictionary.com
late 13c., contraction of Whitsunday.
Whitsunday Look up Whitsunday at Dictionary.com
"Pentecost," late Old English Hwita Sunnandæg "white Sunday" (see white (adj.)); possibly so called from the white baptismal robes worn by newly baptized Christians on this day. Related: Whitsuntide.