The phrase "something that is so delicate that saying its name breaks it" is a metaphor used to describe something that is fragile, ephemeral, or easily disrupted. It can be used to describe something that is difficult to talk about, or that should be handled with care.
It is often used in the context of a secret or a mystery that should not be revealed, as the act of speaking its name could cause it to disappear or lose its power.
The metaphor is also used in the context of a relationship, where it could mean that the relationship is so fragile that talking about it could break it, or it could mean that bringing up certain topics or issues could cause conflict or damage.
It's worth noting that the phrase is often used as a way to express that something is fragile or difficult to talk about, and it's important to be mindful of that delicacy when discussing such matters.