Below the age of 20, acne can cause dark spots due to scarring and red marks left by the infection. Skin Diseases That Cause Dark Spots Melasma: Itâs one of the commonest causes of grayish patches on the face. It mostly affects the forehead, cheeks, or the area between your mouth and nose.
The definition of a titter is a nervous and half-hidden laugh. An example of a titter is the laugh made by a schoolgirl in class. verb. To titter means to laugh or giggle in a somewhat suppressed way. An example of to titter is the laugh of a nervous toddler.
The term has also two other, conflicting meanings. In titration, the titer is the ratio of actual to nominal concentration of a titrant, e.g. a titer of 0.5 would require 1/0.5 = 2 times more titrant than nominal.he titer corresponds to the highest dilution factor that still yields a positive reading. For example, positive readings in the first 8 serial twofold dilutions translate into a titer of 1:256 (i.e., 2 â8).