You probably don’t feel much confusion between jam or jamb, but I’ll explain the difference between the two just in case!
Most people probably wouldn’t admit getting mixed up by the choice of jam or jamb. But jamb is one of those little words that can make you second guess if you think about it too much.
Both words are homophones. Homophones are words we spell differently but pronounce identically. That’s why they can cause confusion.
When you’re stuck in traffic, is that a traffic jam or jamb? If you lean against the frame of a door, is that a jam or jamb supporting your weight? If you wedged something into something else, would you say you jammed or jambed it?
Overthinking some of these word combinations can make the distinctions less clear!
The word jam has multiple meanings. It’s the one we mean to use most of the time.
One of the oldest meanings for jam is as a verb for pressing or wedging something in. That meaning dates back to 1719. That meaning also relates to the sweet preserves that we’re familiar with, which came into English more than a decade later. The Online Etymology Dictionary suggests we might call those sweet preserves jam because they involve the pressing of fruits into that sweet mushy texture.
You can say someone who finds himself in a tight spot could be “in a jam.” That meaning, OED suggests, could be related to being wedged into something. That’s where we get “traffic jams” and “logjams.”
Even the world of jazz got into the act. A jam session refers to an impromptu music performance. This alternate meaning involving jammingi might have come from the preserves definition that refers to “something sweet,” OED says.
The word jam can even refer to blocking broadcast signals, particularly radio signals. That dates back to the 1930s.
The word jamb has two meanings. That’s probably one more meaning than you expected! But it comes from the Old French word jambe, which means “leg” or “vertical support.”
The most common refers to the two vertical sides of a door frame. In the example above, you can lean against the right or left side of a door frame. That’s the jamb.
The alternate definition is a projecting columnar part or mass. Both imply a vertical structure.
Try to avoid a traffic jam if this talk of preserves left you craving some jam as you read this post while leaning against a door jamb.