1) As a verb it could mean to be delayed, as by bad weather and floods.
1488 I wyll thay take in aged folke ... for a neght logyng, or lange, and [if] tha be weder sted or seke, Ingleby Arncliffe
1708 passengers, horsemen as well as footmen must of necessity either stay the falling of the water or else are forced to goe over to the great hazard of their lives, Buckden. More generally it was to prevent, delay, hold back: 1575 the people will not be staied from ringing the bells on All Saints daie, Weaverham
1586 I stayed the suyte I had already commenced against him, Woodsome
1688 took holde of her Apron and staid her, Rotherham. In some contexts the meaning ‘hold back’ was more threatening: 1670 he asked who it was ... I answered one that would stay him ... having an iron forke in my hand said unto him ... that I would stab him, Thurgoland.
2) Support or maintenance, used in the phrase ‘stay of living’ in marriage contracts.