Hello and thanks for posting this.
It is a tooth powder correction, mouthwash bottle. I recall tooth powder from years ago before the Internet but now seeing labeled examples requires me to update my answer!
Many are marked "ODOL" on the bottom - you will find mention online of "Odel" and "Odell" bottles as well
Yours is unusual in that it has a lavender color. Most are milk glass - a pure white color. Older examples have a cork opening without threads.
