affect

As a psychology noun (stress on first syllable): the experience of feeling or emotion, especially as manifested in facial expression or body language; as a verb (stress on second syllable): to have an influence on.

• affective/əˈfɛktɪv/(adj)情感的
• affectation/ˌæfɛkˈteɪʃən/(n)做作

• flat affect
• positive affect
• negative affect
• affect regulation
• affective disorder
• affect display

1. 1.The patient presented with flat affect — speaking in a monotone with no facial expression, as if emotions had been drained from her entirely. (emotional expression)
2. 2.Seasonal affective disorder (SAD) causes depression in winter months, likely triggered by reduced sunlight affecting serotonin and melatonin levels. (emotional/mood disorder)

• emotion/ɪˈmoʊʃən/— a feeling
• mood/muːd/— sustained emotional state
• feeling/ˈfiːlɪŋ/— subjective experience

from Latin "affectus" (state of mind, disposition) — from "afficere" (to do to, to influence) — the state that is done to the mind