How to write an "ß"?
In German there is not a single "proper" way to write letters in handwriting. There are regional variations (see here for details).
For schools in Germany there are federal regulations that define how pupils learn to write. Most widely used are the "Lateinische Ausgangsschrift" and the "Vereinfachte Ausgangsschrift". In these the letter 'ß' is written as follows:
What is the english word for 'Unterlänge'? Upvoting for the underlength! :)
If "Unterlänge" means the part of a letter which extends below the line, you use "descender" in English.
Maybe it's worth noting that `ß` does not have an uppercase form. Instead it's substituted with `SZ`. **Edit:** Whoops, obviously I'm not up-to-date about that.
@Bobby Using *SZ* must be really old style. 40 years ago I already learned to use *SS* instead. Just as *ss* is used in lower case if you don't have a ß on your ancient typewriter.