What Does The Suffix '-en' Mean?

The suffix 'en' is used when you intend to form transitive and intransitive verbs from adjectives and the word can trace its origin in the Middle English period.
     
There are several words that are thankful to this word for their existence and the prime among them are sweetened, heighten and strengthen. If we take the example of the word strengthen, it is used to give strength to something by doing something to the object.
     
The suffix is also used when you intend to form an adjective from the material of the noun. Golden is the prime example of the use of the word in this way.
    
It has some other uses also and the most popular among them is the use of it to form the past participle of many strong verbs.