The term 'emotion' has been derived from the Latin word "emovere" which -means 'to move", 'to excite', 'to stirrup', or 'to agitate'. Arousal-behaviour is emotion, which is an affect-laden state of the organism. "Affect means experience of pleasantness, unpleasantness, excitation, calmness, tension and relaxation" (E.B. Titchener). It is what we mean when we say that we love, fear, and hate. Some of the other emotions are joy, acceptance, surprise, sadness, anger, and disgust etc.
Emotion is a subjective experience of prolonged feelings. What is feeling? In a general way, feeling refers to "experiencing", "sensing" or having a conscious process". Specific meaning of feeling is, (a) 'sensory experience' such as warmth or pain, and (b) 'affective states', such as feeling of well- being, a feeling of depression, and a feeling of desire etc. Wilhelm Wundt stated three dimensions of feelings, such as (i) pleasant or unpleasant, (ii) tense or relaxed, and (iii) excited or depressed. Intense feelings when prolonged turn to be emotions
P.T. Young has operationally defined emotion in the following way: Emotion is an acute disturbance of the organism as a whole, psychological origin involving behaviour, conscious experiences, and visceral functioning. In emotion, the total behaviour including the receptors, effectors nervous systems, and related psychological processes is affected. For example, we have experiences at one time or another the pleasure of see a loved one, the enjoyment of a movie, or the feeling of grief for the sad demise of a dear relation etc. All these experiences represent emotions in spite their subtle differences, and varied characteristics. In other words, emotions are prolonged feelings that generally have both physiological and cognitive elements, which influence behaviour.