Cases of word usage

1) the ability to understand quickly and clearly (acumen)

2) talk that is difficult to understand (e.g. of a baby, people at a party) (babble)

3) to be too difficult for (a person) to do, understand etc (baffle)

4) made up of many connected parts (and often difficult to understand or explain) (complex)

5) to make (something) difficult to do or understand (complicate)

6) to understand (something) fully (comprehend)

7) the state or quality of being difficult; something hard to do or understand (difficulty)

8) a unit of measurement (6 feet or 1.8 meters) of the depth of water; to understand fully (fathom)

9) a way of talking fast that is difficult to understand (gabble)

10) a firm hold or grip; to seize (a person, thing) firmly with the hand(s) or arm(s); to understand (grasp)