In the 1662 edition of the Anglican Book of Common Prayer (described by some as standing with Shakespeare and Milton as one of the great glories of the English language), The Collect for the 2nd Sunday in Advent reads:
Blessed Lord, who hast caused all Holy Scriptures to be written for our learning: Grant that we may in such wise hear them, read, mark, learn, and inwardly digest them, that by patience and comfort of thy holy Word, we may embrace and ever hold fast the blessed hope of everlasting life, which thou hast given us in our Saviour Jesus Christ. Amen.
Unfortunately the compilers of the 1662 edition could not come up with one word, so they used five - and that is the best I can suggest. To read something thoroughly until one understands it well one must 'read, mark, learn and inwardly digest it.