There are undoubtedly hundreds. A Rebus uses this technique, but is probably not the one you are thinking of. Show an example next time.
endsoz
3 letters are DIG in 479 that makes a word.
The hidden meaning in the word "touch" written vertically is "out" - when you read the word from top to bottom, it spells "to u c h" which sounds like "to u tch" or "out." This type of brainteaser is known as a visual or spatial puzzle, where the arrangement of letters or words creates a different meaning when read in a specific way.
dozens
Dozens
under a mat
The letters "ti" in the word "caution" make the "sh" sound.
the word "valuner" rearranged makes the word "unravel"
Those letters will spell percussion and supersonic.
Doornotgot
Ruta is the Kikuyu word for the English word Subtract.
Just f makes the ffff sound, the other letters make up the first part of the word.