A ceiling is the surface above your head in a room, or an upper limit on something, while sealing is the act of closing something securely. Memory hook: a ceiling is the top of the room, over your head, and sealing contains SEAL, as in sealing an envelope.
The core difference
A ceiling is a top surface or upper limit; sealing is closing something up.
- ceiling — the top of a room, or an upper limit: Water stains spread across the bedroom ceiling after the leak.
- ceiling as a limit — a cap on an amount: The government set a ceiling on rent increases.
- sealing — closing something securely: The sealing of the jars is the final step in the canning process.
How to tell them apart
Use ceiling for the overhead surface of a room, and for figurative limits such as a price ceiling or a career ceiling. Think of the space above you.
Use sealing when something is being closed or fastened shut, such as sealing a letter, a jar or a crack. It can also mean the hunting of seals. The mix-up shows up in idioms, where people write glass sealing when they mean glass ceiling. The phrase is glass ceiling.