lock
fastener......lock
The silent letter in "fasten" is the "e." It is written but not pronounced when speaking the word.
The homograph for a device to fasten a door is "bolt." This word can also refer to a type of metal fastener or to move quickly.
Window
Window
sill
A five letter word from the word 'window' is widow.
The silent letter in the word "fasten" is "t." In pronunciation, the "t" is not voiced, making the word sound like "fas-en." This silent letter is a part of English spelling conventions that can sometimes lead to confusion in pronunciation.
The archaic word for "window" is "embrasure." Technically, the word "embrasure" could be used for a window or the opening for a door.
Fusion Fatten Fasten Flaxen Frozen
knocking
No, "fast" is not a root word of "fasten." The word "fasten" comes from the Old English word "faestan," which means "to make firm or secure."