"sudden, violent gust of wind," 1719, originally nautical, probably from a Scandinavian source (compare Norwegian skval "sudden rush of water," Swedish skvala "to gush, pour down"), probably ultimately a derivative of squall (v.).
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).
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Definitions of squally from WordNet
characterized by short periods of noisy commotion;
a home life that has been extraordinarily squally
characterized by brief periods of violent wind or rain;