means Irregular, chaotic motion in air or fluid that causes bumpy, unpredictable movement — most familiar as the jolts that shake an airplane mid-flight.

from From Latin 'turbulentus,' meaning full of commotion or unruly, which grows from 'turba,' a crowd or disorderly throng — the same root that gives us 'disturb' and 'trouble.' So at heart, turbulence is simply a rowdy mob of air, jostling like a crowd that won't settle down.