unruly
adj.difficult to control or keep organized. You use this to describe people who do not follow rules or hair that will not stay neat.
adj.disorderly and disruptive; not amenable to discipline or control. Often used to describe crowds, children, or physical objects like hair that resist grooming.
“The teacher struggled to manage the unruly class.”
“After the game ended in a draw, an unruly crowd gathered outside the stadium to protest the referee's decision.”
“The biographer describes the poet's unruly early years, characterized by a refusal to conform to social expectations and a series of public disagreements with his peers.”
Typically used both attributively before a noun and predicatively after a linking verb like 'become' or 'grow'.
“The Marx Brothers—stage-named Chico, Harpo, Groucho, Gummo and Zeppo—were real-life, unruly brothers from Manhattan’s Upper East Side who were pushed into show business by their mother in the earliest years of the 20th century.”
From Middle English unruly (“unquiet, restless”), equivalent to un- + rule + -ly (compare Middle English ruly, reuli (“subject to a religious rule, regular”)), but also representing a modified continuation of earlier Middle English unrouly, unroly (“unquiet, restless”), equivalent to un- + roolie. The latter is perhaps from or influenced by Old Norse *úróligr, related to Danish urolig (“restless”), Swedish orolig (“restless”), Icelandic órólegur (“agitated”). Compare also Middle English unroo, unro (“unrest”). More at roo.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.