Definitions
There is 1 meaning of the phrase
Filename Extension.
Filename Extension - as a noun
A string of characters beginning with a period and followed by one or more letters; the optional second part of a pc computer filename
Example: "Most applications provide extensions for the files they create"
Synonyms (Exact Relations)
extensionfile name extensionExample Sentences
"The filename extension of the image file is .jpg."
"Make sure to include the correct filename extension when saving the document."
"I can't open this file because it has an unknown filename extension."
"The filename extension for Microsoft Word documents is .docx."
"Please rename the file with a filename extension that indicates its file type."