What does seal mean?
Seal is a versatile English word with several well-established meanings. It can name a marine mammal, especially one seen resting on rocks or ice, as well as a closure or material used to keep a container, room, or opening secure. In legal, governmental, and administrative contexts, a seal is an official stamp or emblem that authenticates a document or demonstrates authority. As a verb, seal means to close or fasten something securely, or to authenticate or formally approve it. The phrase “seal the deal” shows the word’s familiar association with making an arrangement final, while “seal a leak” refers to preventing the escape of liquid or gas. The choice of meaning depends on context: wildlife writing often refers to the animal, practical and engineering contexts emphasize closure, and legal or ceremonial contexts emphasize official authentication.
A marine mammal with a sleek body and flippers, typically living in coastal or polar waters.
"The seal followed the boat through the calm water."
The word can refer to true seals and, in some contexts, to the broader group of pinnipeds.
A device or substance used to close an opening securely.
"Check that the seal around the refrigerator door is intact."
This meaning is common in technical, domestic, and industrial contexts.
An official stamp, emblem, or impression used to authenticate a document or indicate authority.
"The certificate carried the official seal of the university."
Often used in legal, governmental, and ceremonial settings.
To close, fasten, or secure something so that it cannot easily be opened.
"Workers sealed the window before the storm arrived."
The verb can mean preventing the passage of air, liquid, sound, or access.
The plural is seals. It can refer to multiple marine mammals, closures, or official stamps.
"The seals rested on the beach beside their pups."
A seal can mean an ocean predator, a lock against a leak, or the official mark that makes a document legally recognizable.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of seal
The animal meaning comes from Old English seolh, a Germanic word for a seal. The meanings connected with closure and official marking entered English through Old French and Latin terminology associated with sigillum, a seal or signet, and the related verb sigillare, “to seal.” These developments gave modern English its parallel uses for physical closures, authenticated documents, and formal acts of approval.
Related word forms
How seal is actually used
The noun meanings and the verb meaning are both standard in British and American English. In legal and administrative contexts, seal often refers specifically to an official stamp or the act of authenticating a document. As a verb, seal can imply both physical security and formal approval.
Easily confused with seal
Seal means to close or authenticate something securely, whereas steal means to take something without authorization.
Seal is pronounced /siːl/ and means a closure or stamp, while sill is pronounced /sɪl/ and can mean the lower frame of a window or doorway.