A blanket, especially one used as a security blanket.(noun)
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Use "blankie" in a sentence
"Where the brand name came from, I'm not certain, although it certainly sounds like baby talk to me, possibly related to "blankie" -- consider Linus with his blanket wrapped around his arm, and his thumb in his mouth."
"(Of course, my little brother did call his blankie "Tag," cause that's where he clutched it.)"
"The Slanket is a polar-fleece blanket with integrated, outsized sleeves that let you eat popcorn, work the remote, or hold your phone while remaining safely shrouded in blankie."