the wardrobe
The word 'la garde-robe' is used in French to describe a piece of furniture for clothing storage, equivalent to the English word 'wardrobe'. Like most French nouns, it has a gender, in this case feminine, which determines what form of 'the' ('la') to use. It can also refer to one's entire collection of clothes.
I need to organise the wardrobe for autumn.
This sentence means that the speaker needs to arrange their clothes inside the wardrobe to prepare for the autumn season. It implies that the speaker may need to bring out the autumn or heavy clothes and keep the summer or light clothes.
The wardrobe at this hotel is very big.
This sentence is saying that the wardrobe provided at a particular hotel is of larger-than-average size. This could indicate that the hotel is high-end, or that it expects guests to stay for a long duration.
Check inside the wardrobe for the missing coat.
The sentence suggests that a coat has been misplaced and the speaker is advising the listener to check inside the wardrobe (a common storing place for coats). This would be an appropriate instruction in a domestic setting or any circumstance where a coat might have been temporarily stored in a wardrobe.