erratic
/ɪˈræt.ɪk/Not regular, consistent, or predictable. Something erratic changes in a way that is hard to follow or plan for, often causing problems or concern.
- His erratic behavior worried his friends and family.
- The team's erratic performance made it hard to predict results.
- Erratic rainfall has damaged crops across the region.
In geology, an erratic is a large rock that was carried far from its original location by a glacier. It looks out of place because it is different from the rocks around it.
- Scientists studied the erratic to understand ancient glacier movements.
- The lone erratic sat in the valley, far from similar rock formations.
Adinary Nuance
Erratic sits close to "unpredictable," "inconsistent," "irregular," and "volatile," but each word fits a slightly different situation. "Unpredictable" simply means you cannot guess what comes next; "inconsistent" suggests someone or something fails to meet a steady standard; "irregular" is the most neutral — it just means the pattern or timing is uneven. "Erratic" is the strongest of the group: it implies the variation is disorderly and often alarming, not just surprising. In IELTS and academic writing, choose "erratic" when you want to signal that the inconsistency is a serious problem, not just a minor variation.
In other languages
- Vietnamese
- Thất thường
- Spanish
- Errático
- Chinese
- 不稳定的
- Japanese
- 不規則な
- Korean
- 불규칙한
Etymology
From Latin "erraticus," meaning "wandering" or "roving," derived from "errare" (to wander, to make mistakes). The word entered English in the late 14th century and has carried its sense of unpredictable movement or behavior ever since.
Common phrases
Synonyms
Related words
Frequently asked questions
- What is the difference between 'erratic' and 'unpredictable'?
- 'Unpredictable' simply means you cannot guess what will happen next. 'Erratic' is stronger — it suggests the changes are disorderly and often a sign that something is wrong. You would call a person's mood 'erratic' when the swings are extreme and worrying, not just surprising.
- Is 'erratic' formal enough to use in IELTS writing?
- Yes, 'erratic' is well-suited for IELTS Task 1 and Task 2. It is an academic-register word commonly used to describe trends, data, behavior, and economic patterns. It is a good alternative to the simpler word 'unpredictable.'
- Can 'erratic' describe a person?
- Yes, but use it carefully. Calling a person 'erratic' means their actions or mood change in an unpredictable, disorganized way. It carries a negative and sometimes clinical tone, so it is better suited to formal writing or serious conversation than casual speech.
- What is the adverb form of 'erratic'?
- The adverb form is 'erratically.' For example: 'The car was moving erratically down the road.' You can use 'erratically' with action verbs when you want to describe how something behaves, instead of what it is.