overlay

over- +‎ lay. Compare overlie.

Verb

• (Received Pronunciation) enPR: ō'və-lāʹ, IPA^(key): /ˌəʊ.vəˈleɪ/
• (General American) enPR: ō'vər-lāʹ, IPA^(key): /ˌoʊvɚˈleɪ/

Noun

• (Received Pronunciation) enPR: ōʹvə-lā', IPA^(key): /ˈəʊ.vəˌleɪ/
• (General American) enPR: ōʹvər-lā', IPA^(key): /ˈoʊvɚˌleɪ/
• Rhymes: -eɪ

overlay (third-person singular simple present overlays, present participle overlaying, simple past and past participle overlaid or overlayed)

1. (transitive) To lay, spread, or apply something over or across; cover.
   • Edmund Spenser

     as when a cloud his beams doth overlay

   • Milton

     framed of cedar overlaid with gold

2. To overwhelm; to press excessively upon.
   • Sir Walter Raleigh

     when any country is overlaid by the multitude which live upon it

3. (transitive, now rare, archaic) To lie over (someone, especially a child) in order to smother it; to suffocate. [from 14th c.]
   • Bible, 1 Kings iii. 19

     This woman's child died in the night, because she overlaid it.

   • Dryden

     a heap of ashes that o'erlays your fire

   • 1993, Pat Barker, The Eye in the Door, Penguin 2014 (The Regeneration Trilogy), p. 371:

     Prostitutes, thieves, girls who ‘overlaid’ their babies, abortionists who stuck their knitting needles into something vital – did they really need to be here?

4. (transitive, printing) To put an overlay on.

overlay (plural overlays)

1. (printing) A piece of paper pasted upon the tympan sheet to improve the impression by making it stronger at a particular place.
2. (gambling) Odds which are set higher than expected or warranted. Favorable odds.
3. (horse racing) A horse going off at higher odds than it appears to warrant, based on its past performances.
4. A decal attached to a computer keyboard to relabel the keys.
   • 1994, Roger Frost, The IT in Secondary Science Book (page 56)

     The keyboard overlay can be a memory jogger and a great help with spelling. In this way the keyboard makes word processing more accessible to younger as well as special needs children.

5. (programming) A block of program code that is loaded over something previously loaded, so as to replace the functionality.
   • 1986, Noel M. Morris, Computer Graphics and CAD Fundamentals: BBC Micro Version

     This concept can be extended further by allowing a primary overlay to call a secondary overlay, and so on. However, we will limit ourselves here to the use of primary overlays. Before proceeding further, you need to understand the memory map of the computer, which is a diagram showing the use to which the memory of the computer is put.

6. (Internet) A pop-up covering an existing part of the display.
7. (Scotland) A cravat.

overlay

1. simple past tense of overlie

• lay over, layover