Put as an adverb or adjective in 'stay put'?

[Torsten]

Hi,

According to most dictionaries the word put can be either a noun or a verb. Now, what about the idiom 'stay put'? Is 'put' here simply part of the phrase? If so, would you say it's an adverb of adjective?

Thanks a lot,
Torsten

TOEIC listening, photographs: Walking in the snow

[Cerberus™]

According to the ubiquitous OED, it comes from the past participle of "to put", which has turned into an adjective.

[Torsten]

Makes perfect sense. Thanks a lot for that, Cerberus™.

TOEIC listening, photographs: Table tennis