Take a look at this website:
The word for pineapple in virtually every European language is "ananas" or something close to that. Even in Hindi it is "anaanaas" and in Arabic "ananas". Yeah, English is weird.
All male singular adjectives and most male singular nouns end with a -ς. There are also female and neuter nouns (singular again) with a -ς ending but that is not as common. -ς is also used in feminine plural adjectives. Hopefuly you'll learn about these details as the course advances to more compex structures. Keep it up!