One word with many meanings is a homograph.
a homophone
These are homonyms or homophones.
homograph. these are words which are written in the same way but have different meanings.
The word has evolved to have many different meanings, and it can have either a positive or negative connotation
A word that has another word derived from it is called an Eponym. The two words will usually have different meanings.
The word you are looking for is "pun." A pun is a play on words that relies on a word's multiple meanings or on two words that sound similar but have different meanings.
they have different meanings
There are many different meanings of heartache [metaphorical or not] such as:afflictionagonybitternessbroken heartdejectiondepressiondespairdespondencydistressdolorgriefheartbreakheavy hearthurtingmiserypangremorsesadnesssufferingtormenttortureEnjoy.
its connotation
Yes it is. It has different meanings.
A word that is spelled the same with two different meanings is called a homonym.
Homophones are two words that sound the same but are spelled differently and have different meanings. Examples include "they're," "there," and "their."