Pilot Twitter Bird with sad expression

[o an emotional condition, the antonym of "happy". Sadness is often associated with depression, suffering or grief.SAD is a three letter acronym for multiple medical and psychological disorders:Schizoaffective disorderSeasonal Affective DisorderSexual Arousal DisorderSocial Anxiety Disorder.It is also the acronym for an Indian political party, the Shiromani Akali Dal. See more at Wikipedia.org...]

pression may refer to:(in the vernacular) the act or particular way of expressing something (including an emotion through a facial expression or configuration)(in mathematics) a mathematical expression(in computing) a programming language expression(in computing) a vector graphics software Microsoft Expression(in genetics) the effect produced by a gene: gene expression(in grammar) a particular phrase or cliché, whose meaning may be interpretive or idiomatic.(in psychology) the act of expressing emotions.(in industry) obtaining liquids from raw materials through the application of physical pressure See more at Wikipedia.org...