You know that the thing owned is feminine and singular, by the form of the word, but you don't know who owns it since you didn't include the μου/σου/του/της etc. word.
So it could be η δική μου γάτα (my own cat), η δική τους πόρτα (their own door), η δική μας γιαγιά (our own grandmother), or lots of other feminine singular own things belonging to other people.
Thanks, mizinamo. I spoke to a Romanian girl today who just returned to U.S. from Greece. She said she struggled with Greek (modern), especially trying to figure out how to pronounce letters of the alphabet. Since I have some Irish blood, I subscribe to "The Irish never quit" axiom, as it relates here to learning Greek!
There are two issues here. The first and really important one is that the drop down hints are like a dictionary which give more than one definition but they may not all apply to the sentence. So, a good tip is to choose the top word which is most often the correct one. The other is that "fries" refers to "potatoes" that have been fried. We also say "fried potatoes" and more usually "French fried potatoes". Just "fries" is really casual and more popular in Britsh English.
It's been hard for me to get used to the word δικ- being used this way because in Attic Greek δίκη is a lawsuit or a sentence. The accent is different. So then I looked in my modern Gk dictionary and there it was, η δίκη still means lawsuit, case, trial. Reminder that accents matter. Ancient Gk used ἴδιος for possessive pronoun, e.g, τῆν ἴδιαν γυναῖκα, "one's own wife."
what is the difference between (δικές, δικά, δικό) μας?
Gender and number.
Masculine singular: Ο σκύλος είναι δικός μας.
Feminine singular: Η γάτα είναι δική μας.
Neuter singular: Το άλογο είναι δικό μας.
Masculine plural: Οι σκύλοι είναι δικοί μας.
Feminine plural: Οι γάτες είναι δικές μας.
Neuter plural: Τα άλογα είναι δικά μας.
σκύλος (dog) is masculine, γάτα (cat) is feminine, άλογο (horse) is neuter.