polysemy a sigle lexeme is associated with multiple senses. The distinction between homonymy and polysemy is usually made on the basis of the relatedness of the senses: polysemy involves related senses, whereas the senses associated with homonymous lexemes are not related”
(M.Lynne Murphy and Anu Koskela, Key Terms in Semantics. Continuum 2010)
Mouth (of a river vs of a person): related in source, starting point
Cup (of a flower vs of a vassel): related in shape, container with particular round shape
Drive ( a car vs a nail) related, both contain the concept of applying force in a certain direction.
Father he is Ali’s father, he will father this child