in essence

If the human being who answers these tendencies assumes a submissive behavior, in essence a lowering of head and shoulders, wavering glance, absence of all preparations for attack, general weakening of muscle tonus, and hesitancy in movement, the movements of attempt at mastery become modified into attempts at the more obvious swagger, strut and glare of triumph.

1913, Edward Lee Thorndike, Educational Psychology, Teachers college, Columbia university, page 92

The viol, he argued, was in essence a bowed guitar, the result of a cross-fertilisation between the 15th-century Spanish plucked instrument known as the vihuela de mano and the medieval fiddle.

1988, Ian Woodfield, The Early History of the Viol, page 3

The study of the sounds within stars is known as astroseismology, and a separate report in Science details the findings of more than 500 stars whose deep rumblings Kepler has measured. As convection processes within stars move masses of material up from the core, great pressure waves - in essence, sound waves of very low frequency - are created.

2011 April 8, “Kepler star trio find is mystery to astroseismologists”, in bbc.co.uk, retrieved 08 Jan 2013