During meiosis, the state of nucleus having long thread-like chromatin fibres is called interkinesis.

Explanation

### Step-by-Step Solution:

1. **Understanding Meiosis**: Meiosis is a type of cell division that reduces the chromosome number by half, resulting in four haploid cells. It consists of two main stages: Meiosis I and Meiosis II.

2. **Identifying Interkinesis**: Interkinesis is a phase that occurs between Meiosis I and Meiosis II. It is often referred to as Interphase II. During this phase, the cell is not dividing but is preparing for the second meiotic division.

3. **Characteristics of Interkinesis**: During interkinesis, the nucleus contains long, thread-like chromatin fibers. This is a resting phase where the genetic material is not condensed into distinct chromosomes.

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