XmCreatePopupMenu(3) on Linux
The text c75b7f50e624, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A RowColumn widget convenience creation function "XmCreatePopupMenu" "creation functions" "XmCreatePopupMenu"