wiggly (adj.)

early 13c., perhaps from Middle Dutch, Middle Low German, or Middle Flemish wigelen, frequentative of wiegen "to rock, wag, move back and forth," from wiege "cradle," from Proto-Germanic *wig- (source also of Old High German wiga, German Wiege "cradle," Old Frisian widze), from PIE root *wegh- "to go, move, transport in a vehicle." Related: Wiggled; wiggling. The noun is attested from 1816.

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.