Explanation:

- Poise refers to a state of balance, grace, and self-assurance.

- Option 1: Delicate means fragile or easily broken. Not directly opposing poise.

- Option 2: Refinement refers to elegance and improvement, typically enhancing poise.

- Option 3: Calmness is a state of tranquility, often associated with poise.

- Option 4: Instability signifies a lack of balance or steadiness, the direct opposite of poise.