Initialism of Windows Media Audio (file).
"I converted the old music files to wma format so they would play on my computer without any issues."
In plain English: WMA stands for Windows Media Audio, which is an old audio file format that plays music on older computers and some media players.
"I accidentally deleted my favorite songs from that old WMA file on my computer."
Initialism of Wireless Messaging API.
"The developer integrated WMA into their application to enable secure wireless messaging across different devices."