"quick, energetic," 1825, from snap (v.) + -y (2). Meaning "clever, smart" is from 1871; that of "neat and stylishly elegant" is from 1881. Related: Snappily; snappiness. Command make it snappy attested from 1910.
1520s, of animals, "to make a quick bite," from snap (n.). Meaning "to break suddenly or sharply" is first recorded c. 1600; the mental sense is from 1970s. Meaning "come into place with a snap" is from 1793. Meaning "take a photograph" is from 1890. U.S. football sense first recorded 1887. Related: Snapped; snapping. To snap the fingers is from 1670s. Phrase snap out of it recorded by 1907. Snapping turtle is attested from 1784. Snap-brim (adj.) in reference to a type of hat is from 1928.
adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Originally added to nouns in Old English; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy).
<a href="https://www.etymonline.com/word/snappy">Etymology of snappy by etymonline</a>
Harper, D. (n.d.). Etymology of snappy. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/snappy