Verb (5-dan, ぐ, transitive)
1. to stop up; to close up; to block (up); to plug up; to shut up; to cover (ears, eyes, etc.); to close (eyes, mouth)
つい笑いが漏れて、口を塞ぐ。A laugh slipped out, and I covered my mouth.
2. to stand in the way; to obstruct
進路が塞がれたらおしまいだ。If the path is blocked, it's over.
3. to occupy; to fill up; to take up
4. to perform one's role; to do one's duty
Verb (5-dan, ぐ, intransitive)
5. to feel depressed; to be in low spirits; to mope
塞いだ顔をして、どうしたの？You look so down. What's wrong?