Polysemy

Polysemy is the condition of a single lexical item having multiple meaning.
Polysemy is the ability of words to have more than one meaning.
Polysemy or "many meaning" is the name given to this phenomenon, which is not necessarily restricted only to words, but can also be found in morphemes and phrases.
 

When a word or phrase has several meanings, you can describe that word as polysemous. One word that’s famously polysemous is “bank”.

Two Approaches Of Polysemy

Polysemy in diachronic terms implies that a word may retain its previous meaning and at the same time acquire one or several new ones. The main question of diachronic approach is which meaning came first, e.g.
table, n. ‘a flat slab of stone or wood’ (primary meaning); ‘a piece of furniture’, ‘the food put on the table’, ‘people seated at a table’ (secondary meanings).

Synchronically polysemy is understood as co-existence of various meanings of the same word at a certain historical period and the arrangement of these meanings in the semantic structure of a word. Synchronic typology of meaning is concerned with the opposition of main and derived meanings.
 
Example : 

Ø  The house is at the foot of the mountains

Ø  One of his shoes felt too tight for his foot

Bank = bank- pinggiran sungai

Head= kepala(bagian tubuh)- kepala (pimpinan)

Congregation= Jemaah- perkumpulan

Examples

Man

1.      The human species (i.e., man vs. animal)

2.      Males of the human species (i.e., man vs. woman)

3.      Adult males of the human species (i.e., man vs. boy)

Mole

1.      a small burrowing mammal

2.      consequently, there are several different entities called moles

Newspaper

1.      a company that publishes written news.

2.      a single physical item published by the company.

3.      the newspaper as an edited work in a specific format (e.g. "They changed the layout of the newspaper's front page").

Wood

1.      a piece of a tree

2.      a geographical area with many trees

Crane

1.      a bird

2.      a type of construction equipment

3.      to strain out one's neck

References

https://en.wikipedia.org/wiki/Polysemy

http://www.hznu.cn/jpkc/yychx/uploadfiles/CAI/web/unit14.htm

http://mybiblioteka.su/tom2/3-98023.html

https://ciu.nstu.ru/.../146647%3Fnomenu%3D1