If "seal" refers to the animal:
* No opposite: There isn't a specific animal that is the direct opposite of a seal. You could consider other marine mammals like whales or dolphins, but they aren't truly opposites.
If "seal" refers to the act of sealing:
* Open: This is the most direct opposite, as it refers to the state of not being sealed.
* Unseal: This is the action of removing a seal.
* Unpack: This refers to opening a sealed package or container.
* Reveal: This implies making something previously concealed visible.
If "seal" refers to a stamp or mark:
* Unmark: This indicates the removal of a seal or mark.
* Erase: This implies removing a seal completely.
It's important to consider the specific context to determine the most appropriate opposite.