Homophone word are words that are pronounced in the same way, but written differently, and have different meanings. Thus, they have different spelling and meaning, but have the same phonetics.
Here are some examples:
1 - Acento / assento
Acento= a graphic sign (Ex.: The acute accent is one of the most used in the Portuguese language.)
Assento = place to sit (Ex.: The seat was occupied.)
2 - Cinto / Sinto
Cinto = accessory for pants (Ex: The brown belt matched perfectly with the shoe.)
Sinto = verb to feel (Ex: I am sorry for what happened.)
6 - Concerto / Conserto
Concerto = musical presentation (Ex: The orchestra's concert was spectacular.)
Conserto = repair (Ex: The bicycle repair will be expensive.)
This is very interesting from the linguistic point of view. When speaking, the context determines which word is being used. Some others I know are:
Vós: second-person plural (in the European variety)
Cem: one hundred
Is a word considered a Homophone if it has two meanings but is written the same?
the word ‘Manga’
No, when words are spelled the same way, but have different meanings we call them homograph words: same spelling, but different pronunciation.
Keep in mind we also have those in English! For example Break/Brake or Wear/Where
Maybe comparing both languages will help you understand Portuguese homophones better, too
That’s a really good suggestion and perhaps a good way to have a better understanding of both languages.