How do you abbreviate the word conditions?

There isn't a widely accepted abbreviation for "conditions." You can use the following options depending on the context:

Formal:

* Conds. (if the context makes it clear what you mean)

* Cond. (if referring to a specific condition)

Informal:

* Conds. (less common)

* Cnd. (very informal)

However, it's usually best to avoid abbreviations unless you are sure they will be understood by your audience. In most cases, using the full word "conditions" is clearer and more professional.