keeper

Etymology

From Middle English kepere, equivalent to keep + -er.

noun

1. One who keeps (retains) something.
   Finders keepers; losers weepers.
2. One who remains or keeps in a place or position.
   I was not altogether surprised: they seemed to be, even more than people in the surrounding wolds, stolid keepers-to-themselves, impossible to stir, dourly determined to stick to the firm routine of their lives[…] 1971, H. R. F. Keating, The Strong Man
3. A fruit or vegetable that keeps (remains good) for some time without spoiling.
   Roxbury Russet: Market and keeper. c. 1847, Andrew Jackson Downing, The Fruits and Fruit Trees of America
   And mark you, good keepers are some years bad keepers, as this year; and a hard, heavy, unbruisable Apple that really will keep to late on in the season is doubly valuable. 1878, Journal of Horticulture and Practical Gardening, volume 35, page 331
4. (informal) A person or thing worth keeping.
   "Okay, that's a keeper," Harold said as he netted the 3-pounder and put him on a stringer over the side of the boat. 1970, Field & Stream, volume 75, number 7, page 76
   When he brought me home and volunteered to come with me while I walked my dog, Max, I knew he was a keeper. 2005, Ladies' Home Journal, volume 122, numbers 7-12, page 101
   We hadn't dated for long when he said those three magic words: "I'll cook tonight." I knew he was a keeper. 2008, Jennifer Zomar, A Candle for the Children, page 28
5. A person charged with guarding or caring for, storing, or maintaining something; a custodian, a guard; sometimes a gamekeeper.
   The inquest on keeper Davidson was duly held, and at the commencement seemed likely to cause Tony Palliser less anxiety than he had expected. 1907, Harold Bindloss, chapter 4, in The Dust of Conflict
6. (sports) The player charged with guarding a goal or wicket. Short form of goalkeeper, wicketkeeper.
   England should have capitalised on their growing momentum to win, but Darren Bent failed to reproduce the finishing touches that have brought him goals in three successive appearances. He was blocked by Diego Benaglio when he was played in by Wilshere then blazed over the top of an open goal late on after Young's shot was saved by Switzerland's keeper. June 4, 2011, Phil McNulty, “England 2 - 2 Switzerland”, in BBC
7. A part of a mechanism that catches or retains another part, for example the part of a door lock that fits in the frame and receives the bolt.
8. A thin, flexible tress or tongue of material (e.g. leather) at the end of a crop opposite the handle, which is broad enough to prevent the horse's skin from being marked as it might be by a whip.
   The all-whalebone crop, braided with gut, pigskin handle, single brown stitched leather keeper, and close[…] 1912, Minnie McIntyre, Edward E. Wood, Alexander Henry Waddell, Wilfred Jay, Wilfred P. Pond, Bit & Spur, page 39
   “When we catch you—” A brief but vivid fantasy of the nose-ringed girl trailing a riding crop's cool leather keeper over her clenched and trembling ass shoved its way eagerly into Fran's imagination. “—we're gonna[…]” 2022-02-22, Gretchen Felker-Martin, Manhunt, Tor Nightfire
9. (American football) An offensive play in which the quarterback runs toward the goal with the ball after it is snapped.
10. Synonym of armature (“piece of metal connecting the poles of a magnet to preserve its strength by forming a circuit”)
    The continuous lines indicate the moments, when the magnet and keeper of equal diameter (10.5mm) act upon each other […] 1878, Oluf Andreas Løwold Pihl, On Magnets (page 94)