Sink (one's) teeth into (something) informal verb phrase
To get very involved in something with one's utmost energy, determination, or enthusiasm
That project is interesting. I can't wait to sink my teeth into it.
I'm recently sinking your teeth into a really good book about reincarnation.
Adequate measures or actions
To do one's best or try one's best to do something
If you desire something good or appealing, you must make the necessary effort to acquire it.
To work really hard in order to attain something.
The verb "sink" should be conjugated according to its tense.
This metaphor refers to a predatory animal biting down hard on its prey. [Early 1900s]
A humorous way of saying that what one has said is just what they acknowledge and may not be entirely accurate
Mike: Have you returned from your vacation on the beach? Your skin seems to get tanned.
Jenny: My skin is always dark. That's my story and I'm sticking to it!