fulcrum

Etymology

Borrowed from Latin fulcrum (“bedpost, foot of a couch”), from fulciō (“prop up, support”).

noun

1. (mechanics) The support about which a lever pivots.
   It is possible to flick food across the table using your fork as a lever and your finger as a fulcrum.
   MILDRED: Archimedes said give me a lever long enough and a fulcrum on which to place it and I will move the world. CHARLOTTE: Yeah she said that twaddle eight or nine times. 2010, John Allison, Bad Machinery
   A doorknob of whatever roundish shape is effectively a continuum of levers, with the axis of the latching mechanism—known as the spindle—being the fulcrum about which the turning takes place. 2012-03, Henry Petroski, “Opening Doors”, in American Scientist, volume 100, number 2, pages 112–3
2. (figurative) A crux or pivot; a central point.
   By this point the fulcrum of concern is the stuprum of men upon men, described as more prevalent than that upon women. 2006, Rebecca Langlands, Sexual Morality in Ancient Rome, page 119
   Chelsea's Mason Mount is a top-class talent while West Ham midfielder Declan Rice has moved his game on to another level this season and will be the fulcrum of England's midfield this summer. 31 March 2021, Phil McNulty, “England 2-1 Poland: What shape are Gareth Southgate's side in?”, in BBC Sport