الصلاة
Prayer or supplication, depending on the governing convention.
In religious terminology, ṣalāh is a prescribed act comprising a structured set of words and actions. Supplication is associated with this act and can be considered part of what it encompasses. Calling a mere supplication “ṣalāh” in a context governed by the ritual sense may therefore raise a part–whole question.
The key is not whether “ṣalāh” has ever meant supplication lexically; it is which assigned meaning governs this utterance. Literalness in one convention does not automatically determine the status of every occurrence in another.