erratic

comparative more erratic · superlative most erratic · alternative erratick · alternative erraticke · alternative erratique

1. Unsteady, random; prone to unexpected changes; not consistent.

   Henry has been getting erratic scores on his tests: 40% last week, but 98% this week.

   2 more examples

   When we found you on the street, your behavior was all erratic and it seemed like you were having a panic attack.

   The V-2's directional system was notoriously erratic. In May 1947, a V-2 launched from White Sands Proving Ground headed south instead of north, missing downtown Juarez, Mexico, by 3 miles.

   2010, Mary Roach, “You Go First: The Alarming Prospect of Life Without Gravity”, in Packing for Mars: The Curious Science of Life in the Void, W. W. Norton & Company, →ISBN, page 90

   Synonyms: mercurial

2. Deviating from normal opinions or actions; eccentric; odd.

   erratic conduct

   1 more example

   Investigators were careful not to rule out Bryce’s erratic behaviour in his final days, including the giveaways, the sudden breakup, and the hours spent parked by the side of the freeway. These factors pointed to a mental health crisis severe enough that he wanted to disappear.

   2026 July 18, Nicholas Muhoro, “Bryce Laspisa Vanished Near Castaic Lake After Spending 13 Hours Parked on a California Highway”, in Skip Boring, archived from the original on 19 Jul 2026

plural erratics · alternative erratick · alternative erraticke · alternative erratique

1. geographyA rock moved from one location to another, usually by a glacier.

   The term for a displaced boulder is an erratic, but in the nineteenth century the expression seemed to apply more often to the theories than to the rocks.

   2003, Bill Bryson, A Short History of Nearly Everything, BCA, page 372

   1 more example

   During the last ice-age, massive stones were carried for miles by the scouring glaciers, only to be left, like passengers at the end of the line, when the glaciers retreated. Stranded in their new surroundings with rocks with which they share no common geology, their out-of-place-ness is evoked by their name: “erratics”.

   2015 May 4, Dominick Tyler, “10 UK landscape features that you’ve probably never heard of”, in The Guardian

   Synonyms: dropstone

2. Anything that has erratic characteristics.