Wiktionary
vb. 1 To research a particular subject. 2 To heartily begin eating.
WordNet
Usage examples of "dig into".
She frowned a little and gave her trowel a rather spiteful dig into the earth.
Bullets wound the earth and dig into it, trembling with impatience.
But just think, you'll have the whole library at the hospital to dig into any time you want it!
But every Heechee tunnel is the same, and if you dig into them from the outside you find the same basic substrate rock, then a boundary layer that's sort of half wall-metal and half substrate, then the wall itself.
The heads of the birds dig into the belly and joints of the antelope, pushing right inside the carcass.
The bucket was dirty, the pot was dirty, the hands he'd felt Agnes's wound with were dirty, and, standing there, watching him set the pot on the fire and dig into a dirty bag, I was sorry I'd come.