Etymology
Advertisement
too (adv.)
"in addition; in excess," a variant of to (prep.) originally used when the word was stressed in pronunciation. In Old English, the preposition (go to town) leveled with the adverb (the door slammed to). Most of the adverbial uses of to since have become obsolete or archaic except the senses "in addition, besides" (Old English), "more than enough" (c. 1300). As this often fell at the end of a phrase (tired and hungry too), it retained stress and the spelling -oo became regular from 16c.

Use after a verb, for emphasis (as in did, too!) is attested from 1914. Slang too-too "excessive in social elegance" first recorded 1881. Too much is from 1530s as "more than can be endured;" sense of "excellent" first recorded 1937 in jazz slang. German zu unites the senses of English to and too.
Related entries & more 
Advertisement
overlong (adj.)

early 14c., of text, "too lengthy, requiring too much time, very tedious;" from over- + long (adj.). From late 14c. as "lasting too long." Middle English had also overshort "too short, too brief."

Related entries & more 
overuse (n.)

also over-use, "too much or too frequent use," 1824, from over- + use (n.).

Related entries & more 
overstrong (adj.)

"too powerful, too harsh," c. 1200, originally of medicines and remedies, from over- + strong (adj.).

Related entries & more 
overdone (adj.)

late Old English ofer-done "carried to excess, immoderate, too much;" see overdo. Of meat, etc., "cooked too much," from 1680s.

Related entries & more 
Advertisement
overwrought (adj.)

of feelings, imagination, etc., "worked up to too high a pitch, overexcited," 1758, literally "over-worked, worked too hard or too much," from over- + wrought. Earlier it meant "exhausted by work" (1660s), of oxen, etc., as a literal past participle of overwork (v.).

Related entries & more 
crybaby (n.)

also cry-baby, derisive word for one who cries too easily or too much, 1851, American English, from cry + baby (n.).

Related entries & more 
underestimate (v.)
1812, "to estimate at too low an amount," from under + estimate (v.). Meaning "to rank too low, undervalue" is recorded from 1850. Related: Underestimated; underestimating.
Related entries & more 
overstrung (adj.)

also over-strung, 1767 of musical instruments, "with strings too tense;" 1801, of persons, "too sensitively organized," from over- + strung. In the figurative extension, the notion is the one in the colloquial expression wound too tight.As a type of pianowith string sets crossing each other obliquely, by 1860.

Related entries & more 
overuse (v.)

also over-use, "use too much or too frequently; injure by excessive use," 1670s, from over- + use (v.). Related: Overused; overusing.

Related entries & more