"small particle, as of dust visible in a ray of sunlight," Old English mot, of unknown origin; perhaps related to Dutch mot "dust from turf, sawdust, grit," Norwegian mutt "speck, mote, splinter, chip." Hence, anything very small. Many references are to Matthew vii.3.
First attested in phrases such as heir apparent (see heir). Meaning "superficial, spurious" is from c. 1400; that of "appearing to the senses or mind but not necessarily real" is from 1640s. Apparent magnitude in astronomy (how bright a heavenly body looks from earth, as opposed to absolute magnitude, which is how bright it really is) is attested from 1875. Middle English had noun forms apparence, apparency, but both are obsolete from 17c.
"pertaining to the sun" (but used especially of stars, in reference to their becoming visible out of the sun's glare), c. 1600, with -al (1) and Latinized form of Greek hēliakos "of the sun," from hēlios "sun" (from PIE root *sawel- "the sun"). The heliacal year (used in ancient Egypt) is reckoned from the heliacal rising of Sirius; thus it also is known as the canicular year. Related: Heliacally (1580s).
early 15c., "ready, prepared (to do something), quick to act as occasion demands," from Old French prompt (13c.) and directly from Latin promptus "brought forth," hence "visible, apparent, evident, at hand," past-participle adjective from promere "to take or bring out or forth" (see prompt (v.)). Meaning "given or performed without delay" is from 1520s. Related: Promptly.
early 15c., disaperen, "cease to be visible, vanish from sight, be no longer seen," from dis- "do the opposite of" + appear. Earlier was disparish (early 15c.), from French disparaiss-, stem of desapparoistre (Modern French disparaître).
Transitive sense, "cause to disappear," is from 1897 in chemistry; by 1948 of inconvenient persons. Related: Disappeared; disappearing; disappears. Slang disappearing act "fact of absconding, action of getting away," is attested by 1884, probably originally a reference to magic shows.
