actual |ˈak ch oōəl|adjective1 existing in fact; typically as contrasted with what was intended, expected, or believed : the estimate was much less than the actual cost | those were his actual words. See note at genuine .• used to emphasize the important aspect of something : the book could be condensed into half the space, but what of the actual content?2 existing now; current : using actual income to measure expected income.PHRASESin actual fact used to emphasize a comment, typically one that modifies or contradicts a previous statement : people talk as if he were a monster---in actual fact he was a very kind guy.ORIGIN Middle English : from Old French actuel ‘active, practical,’ from late Latin actualis, from actus (see act ).
aisthesis | sensation, perception, as an opposite of intellection ( noesis), understanding and pure thought; more loosely – any awareness; for Plato, some aistheseis have names, such as sights, sounds, smells, cold and heat, distress, pleasures, fears, but nameless aistheseis are countless ( Theaet.156b); for Plotinus, perceptions in this world are dim intellections ( noeseis), and intellections in the noetic world are vived perceptions; Philo of Alexandria postulates an Idea of aisthesis, along with an Idea of nous, in the Intellect of God ( Leg.Alleg.I.21-27).
birefringent |ˌbīriˈfrinjənt|adjective Physicshaving two different refractive indices.
para- 1 (also par-)prefix1 beside; adjacent to : parameter | parataxis | parathyroid.• Medicine denoting a disordered function or faculty: : paresthesia.• distinct from, but analogous to : paramilitary | paraphrase | paratyphoid.• beyond : paradox | paranormal | parapsychology.• subsidiary; assisting : paramedic | paraprofessional.2 Chemistry denoting substitution at diametrically opposite carbon atoms in a benzene ring, e.g., in 1, 4 positions : paradichlorobenzene. Compare with meta- and ortho- .ORIGIN from Greek para ‘beside’ ; in combinations often meaning ‘amiss, irregular’ and denoting alteration or modification.para- 2 |ˈparə|combining formdenoting something that protects or wards off : parachute | parasol.ORIGIN from French, from the Italian imperative singular of parare ‘defend, shield’ (originally meaning ‘prepare,’ from Latin parare).
refraction | riˈfrak sh ən |noun Physicsthe fact or phenomenon of light, radio waves, etc., being deflected in passing obliquely through the interface between one medium and another or through a medium of varying density.
• change in direction of propagation of any wave as a result of its traveling at different speeds at different points along the wave front.
• measurement of the focusing characteristics of an eye or eyes.
ORIGIN mid 17th cent.: from late Latin refractio(n-), from refringere ‘break up’ (see refract ).
transitive |ˈtransitiv; ˈtranz-|
adjective
1 Grammar (of a verb or a sense or use of a verb) able to take a direct object (expressed or implied), e.g., saw in he saw the donkey. The opposite of intransitive .
2 Logic & Mathematics (of a relation) such that, if it applies between successive members of a sequence, it must also apply between any two members taken in order. For instance, if A is larger than B, and B is larger than C, then A is larger than C.
transitive |ˈtransitiv; ˈtranz-|
adjective
1 Grammar (of a verb or a sense or use of a verb) able to take a direct object (expressed or implied), e.g., saw in he saw the donkey. The opposite of intransitive .
2 Logic & Mathematics (of a relation) such that, if it applies between successive members of a sequence, it must also apply between any two members taken in order. For instance, if A is larger than B, and B is larger than C, then A is larger than C.
virtual |ˈvər ch oōəl|adjective almost or nearly as described, but not completely or according to strict definition : the virtual absence of border controls.• Computing not physically existing as such but made by software to appear to do so : a virtual computer. See also virtual reality .• Optics relating to the points at which rays would meet if produced backward.• Physics denoting particles or interactions with extremely short lifetimes and (owing to the uncertainty principle) indefinitely great energies, postulated as intermediates in some processes.DERIVATIVESvirtuality |ˌvər ch oōˈalitē| |ˈvərtʃəˈwølədi| |-jʊˈalɪti| nounORIGIN late Middle English (also in the sense [possessing certain virtues|possessing certain virtues] ): from medieval Latin virtualis, from Latin virtus ‘virtue,’ suggested by late Latin virtuosus
para- 1 (also par-)prefix1 beside; adjacent to : parameter | parataxis | parathyroid.• Medicine denoting a disordered function or faculty: : paresthesia.• distinct from, but analogous to : paramilitary | paraphrase | paratyphoid.• beyond : paradox | paranormal | parapsychology.• subsidiary; assisting : paramedic | paraprofessional.2 Chemistry denoting substitution at diametrically opposite carbon atoms in a benzene ring, e.g., in 1, 4 positions : paradichlorobenzene. Compare with meta- and ortho- .ORIGIN from Greek para ‘beside’ ; in combinations often meaning ‘amiss, irregular’ and denoting alteration or modification.para- 2 |ˈparə|combining formdenoting something that protects or wards off : parachute | parasol.ORIGIN from French, from the Italian imperative singular of parare ‘defend, shield’ (originally meaning ‘prepare,’ from Latin parare).