Translation guide
The act of closing or fastening something securely, often to prevent opening, leakage, or tampering. This guide covers common Japanese expressions for sealing containers, envelopes, joints, and surfaces.
To seal an envelope, box, or container by closing it with adhesive, tape, or a sticker.
General phrase meaning 'to seal' or 'to close with a seal'. Commonly used for envelopes and containers.
Please seal the envelope.
Means 'to close' or 'to shut'. Used for envelopes, books, etc., but does not necessarily imply a seal.
Please close the envelope.
Loanword from English 'seal', often used for sealing with stickers or tape.
I sealed the box with tape.
To seal a container, joint, or surface to prevent air, water, or other substances from passing through.
Specifically means 'to seal tightly' or 'to make airtight/watertight'. Used for food containers, packages, etc.
Store food in an airtight container.
Similar to 密封する, meaning 'to seal tightly' or 'to close hermetically'. Often used in technical contexts.
Please seal the container tightly.
Means 'to pack' or 'to seal with packing material'. Used for plumbing or mechanical seals.
Seal the pipe joint with packing.
To affix a seal, stamp, or sticker as a mark of authenticity, approval, or closure.
Means 'to seal' with a formal seal or stamp, often for legal or official documents. Implies a mark that must be broken to open.
I put a seal on the document.
Specifically means 'to affix a seal' or 'to stamp'. Used for personal or company seals (hanko).
Please affix your seal to the contract.
Refers to using sealing wax, often for decorative or traditional purposes.
I used sealing wax on the letter.
To block or close off an area, entrance, or passage so that it cannot be used or entered.
To finalize or confirm an agreement, often with a handshake or formal act.
Means 'to conclude a contract' or 'to seal a deal'. The most natural way to express finalizing an agreement.
The two companies sealed the deal.
Means 'to reach an agreement'. Less formal than 契約を結ぶ, but still implies finalization.
After negotiations, they sealed the agreement.
Literally 'to decide with a handshake'. Used for informal agreements, similar to 'seal with a handshake'.
We sealed the deal with a handshake.
Both mean 'to seal tightly', but 密封する is more common for everyday items like food containers, while 密閉する is often used in technical or industrial contexts (e.g., hermetically sealed).
This container has a high sealing property.
シールする is a casual loanword for sticking or taping. For official seals or stamps, use 封印する or 捺印する.
It's inappropriate to 'seal' a document with a sticker.