Fashion has a complicated vocabulary of signs and signifiers. Fashion mag-editors tend toss around phrases like haute couture or panniers, never once worrying that their readers have no idea what they are talking about. But all of that is about to change because Fashion 101 starts today.

Your first lesson? The leg-of-mutton-sleeve.

The leg-of-mutton sleeve is constructed with a full top that is gathered into the armhole. The fabric then tapers gradually to tuck in closely at the wrist, which gives the sleeve the bell-shaped outline, just like a leg of mutton. This type of sleeve was first seen in 1824, but eventually made a comeback in the swinging days of the 1890s.

While modern day designers have mostly abandoned the leg-of-mutton sleeve (what woman wants her shoulders to look like Sunday dinner?), you can occasionally catch glimpses of the leg-of-mutton-sleeves in certain Victorian-inspired clothes.