dot¹ / dät/ • n. a small round mark or spot: a symbol depicted in colored dots. ∎  such a mark written or printed as part of an i or j, as a diacritical mark, as one of a series of marks to signify omission, or as a period. ∎  Mus. such a mark used to denote the lengthening of a note or rest by half, or to indicate staccato. ∎  the shorter signal of the two used in Morse code. Compare with dash (sense 3). ∎  used to refer to an object that appears tiny because it is far away: the desert shrank figures to mere dots. ∎  used in speech to indicate the punctuation separating parts of an electronic mail or Web site address.• v. (dot·ted , dot·ting ) [tr.] mark with a small spot or spots: wet spots of rain began to dot his shirt. ∎  (of a number of items) be scattered over (an area): churches dot the countryside. ∎  place a dot over (a letter): you need to dot the i. ∎  Mus. mark (a note or rest) to show that the time value is increased by half: [as adj.] (dotted) a dotted quarter note. PHRASES: dot the i's and cross the t's inf. ensure that all details are correct.on the dot inf. exactly on time: he arrived on the dot at nine o'clock.DERIVATIVES: dot·ter n.dot² • n. archaic a dowry, particularly one from which only the interest or annual income was available to the husband.

dot, dotted note. Mark in notation. (1) Placed above a note indicates staccato. (2) Placed after a note lengthens it by half. But in music up to and including Bach and Handel the addition intended was merely approximately half, something being left to the decision of the performer, e.g. a dotted quaver and a semiquaver in one part, played against a triplet of quavers in another part, might accommodate itself to that latter rhythm,being rendered thusAlso in a very slow movt. .♪ might be rendered .. . It was, indeed, to meet this latter case that the DOUBLE DOT (the 2nd dot adding half the value of the 1st one) was introduced in 1769 by Mozart's father, Leopold Mozart.

dot dot-com a company that conducts its business on the Internet. The term comes (in the 1990s) from ‘.com’ in an Internet address, indicating a commercial site.
dot the i's and cross the t's ensure that all details are correct; the phrase is recorded from the mid 19th century.

See also sign on the dotted line.

dot 1 (dial.) small lump, clot XVI; minute mark XVII. OE. dott (once) head of a boil, perh. in continuous colloq. use, but not recorded again till XVI in the gen. sense of ‘small knob or lump’, when its appearance may be due to Du. dot knot, prob. rel. to OHG. tutto, tutta nipple; for the prob. base *dutt- cf. OE. dyttan (:- *duttjan), dial. dit stop up, plug.
Hence dot vb. XVIII.

DOT • abbr. Department of Transportation.