Is there a name for words like "hearsay"

These could be called compound single-word verbs, to differentiate from other compound words such as moonlight (though, admittedly, to moonlight is a verb, albeit a noun-noun compound).

Example of verb-verb compound verbs: stirfry.

In linguistics, there's a technical term "serial verb constructions" (SVC). This paper aims to show that verb-verb compounds in English (and Jordanian Arabic) are examples of SVC. It gives other examples: kickstart, crash-land, sleep-walk.