Etouffée is French and means damped. The term is used to describe a damping technique used to damp one note after the other in order to get a sort of "portato" articulation in a line or a melody.
The right and left hand produce the etouffée effect differently.
The harpist keeps the palm of the hand open and plays the note with the thumb. The palm of the hand and the remaining fingers damp the note shortly after it is played.
Etouffée in the left hand, downwards/upwards.
The right hand's second finger plays the note. In an upwards moving phrase or melody the knuckle of the second finger damps the note as soon as the second finger plays the next note. In a downwards moving phrase or melody the thumb damps the previous note. Unlike the left hand, the right hand can only play etouffée if the phrase in question is a continuous scale up or down.
Etouffée in the right hand, upwards/downwards.
Etouffée is notated by writing the word etouffée above or below the notes in question and adding a plus sign.
The whole harp.
Playing etouffé requires precision and is a considerable action for the harpist. Therefore playing etouffe considerably slows the maximum speed of playing successive pitches.