Unlike langauges like German, English is said to lack the ability to make a new word by simply piling on other words onto another. Thanks to noun agglutination and the ease of making more specific words out of different existing words, German can make words like Rindfleischetikettierungsüberwachungsaufgabenübertragungsgesetz (their term for a cattle marking and beef labeling supervision duties delegation law).
What English does have, however, is our own compound words, which coupled with English’s amazing ability to coin new words, is pretty much the same thing but without the ability to keep adding words almost indefinitely. Words like “afternoon”, “bathroom”, “blackboard”, “blueprint” and “brainstorm” are everyday compound words, but if after lunch one day you came up with some good ideas in a classroom, you couldn’t call it an “afternoonblackboardbrainstorm”.
Though limited in how they’re formed, there are thousands of compound words in the English language, and nowadays there always seems to be more coming into popular usage. 30 years ago words like “internet”, “broadband” and “microsoft” would not have much special meaning, but they’re part of common English parlance nowadays.
Compound words aren’t to be confused with portmanteaus, which is where 2 other words are blended together to make one single word (e.g. “smog” (smoke + fog)), rather than keeping both of the words intact.