A fisher is someone who catches fish, and it is also the name of a North American mammal. A fissure is a long, narrow crack or split. Fisher has fish in it; fissure is related to fission, which is about splitting.
The core difference
A fisher is a person who catches fish (or a weasel-like mammal), whereas a fissure is a narrow crack or split in rock, ground or a group.
- fisher — someone who catches fish, or a North American mammal: Local fishers rely on the salmon run every autumn.
- fissure — a long, narrow crack or split: A deep fissure had opened in the volcanic rock.
How to tell them apart
Fisher and fissure are homophones: they are pronounced the same in standard speech, so the sound will not tell you which one is meant. Only the spelling and the context do that, and the meanings are very different.
To keep them straight, look for fish inside fisher, and link fissure with fission, since both come from a Latin root meaning to split. Fissure can also be figurative, as in a fissure within a political party, meaning a serious split between people.
