mainstays

Noun

mainstay (plural mainstays)

1. A chief support.
   • Agriculture is the mainstay of this country’s economy.
2. Someone or something that can be depended on to make a regular contribution.
   • On the Bishops Stortford line, the crisis now seems to be over; the units designed for this service are the mainstay of the workings once again and although some of the inner suburban sets are still seen, very few L.T.S. Line units are noticeable.1963 January, “Motive power miscellany”, in Modern Railways, page 65
3. A stabilising rope from high on the mainmast to the base of the foremast.