The substitute teacher faced unruly students in the classroom.
Tried to comb his unruly hair; trimmed back the unruly bushes.
A group of pre-schoolers who are running around and being very wild are an example of students who would be described as unruly.
Origin of unruly
From American Heritage Dictionary of the English Language, 5th Edition
- From Middle English unruly (“unquiet, restless"), interpreted as 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- +"Ž roolie. The latter is perhaps from or influenced by an Old Norse word related to Danish urolig (“restless"), Swedish orolig (“restless"), Icelandic Ã³rÃ³legur (“agitated"). Compare also Middle English unroo, unro (“unrest"). More at roo.