Your wallet doesn't store your coins (that's actually the beauty of it!). Rather, it stores the ability to access and transact with your coins (i.e. your keys).
A compromised seed is one that has been exposed or has the potential to be exposed by a third party (in other words, if someone else has seen it or someone might be able to see it in the future).
First of all, don't panic. It's not the end of the world.
Take account of your situation:
Do you still have the device your wallet is on and access to your wallet?
A seed phrase is an ordered set of 12-24 words that is generated by your wallet and stores all the information that can be used to recover your wallet.
For the most part, seed phrases follow Bitcoin Improvement Proposal: 39 (BIP 39). BIP 39 standard describes the process in how a mnemonic phrase (a group of easy to remember words) is generated and can be used to recover your wallet in the event your wallet fails.
You may think a seed phrase is a bunch of randomly chosen words.
It is! But it also, isn't.