shifty adj.

c. 1300, "a movement, a beginning," from shift (v.); by mid-15c. as "an attempt, expedient, or means." This is the word in make shift "make efforts" (mid-15c.; see makeshift). The specific sense of "means to an end" is from 1520s, hence "a device, a trick." The sense of "change, alteration" in character, place, position, etc., is from 1560s.

The meaning "mechanism for changing gear in a motor vehicle" is recorded from 1914. Typewriter shift key is so called by 1893; its shift-lock is so called from 1899.

The meaning "period of working time" (originally in a mine) is attested from 1809, perhaps from or influenced by an older sense "relay of horses" (1708); perhaps also influenced by a North Sea Germanic cognate word (such as North Frisian skeft "division, stratum," skaft "one of successive parties of workmen"). Similar double senses of "division" and "relay of workers" is in Swedish skift, German schicht.

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). Adjectives such as hugy, vasty are artificial words that exist for the sake of poetical metrics.