Learn Icelandic: Við þrífum karlaklefann og kvennaklefann. - We clean the men's locker room and the women's locker room.

This compound noun is made of karl (man) and klefi (room or cubicle). Because it is a room for multiple men, the first word takes the plural genitive (possessive) form, which is karla (of men). That final -a acts as the linking vowel connecting it to the second half of the word.

Where does the kvenna- part of kvennaklefann come from?

It comes from the word kona (woman). The plural genitive form of kona is highly irregular: kvenna (of women). Just like with the men's room, we use this plural genitive form as the first half of the compound to link the two words together, creating kvennaklefi.

Why do the compound nouns end in -ann in this sentence?

The verb þrífa (to clean) forces its object into the accusative case. The core noun here is klefi, which is a masculine weak noun. Its accusative singular form is klefa, and when you add the masculine accusative definite article suffix to mean "the", it becomes klefann.

Does the root word klefi specifically mean "locker room"?