Fathom /(făth"ŭm)/

1. A measure of length, containing six feet; the space to which a man can extend his arms; -- used chiefly in measuring cables, cordage, and the depth of navigable water by soundings.
2. The measure or extant of one's capacity; depth, as of intellect; profundity; reach; penetration. [R.]

   Another of his fathom they have none To lead their business.

imp. & p. p. Fathomed; p. pr. & vb. n. Fathoming

1. To encompass with the arms extended or encircling; to measure by throwing the arms about; to span. [Obs.]
2. To measure by a sounding line; especially, to sound the depth of; to penetrate, measure, and comprehend; to get to the bottom of.

   The page of life that was spread out before me seemed dull and commonplace, only because I had not fathomed its deeper import.