Sentence:  Thus, when he drew up instructions in lawyer language, he expressed the important words by an initial, a medial, or a final consonant, and made scratches for all the words between; his clerks, however, <WSD>understood</WSD> him very well. 
Meaning of the word marked with <WSD> tags:  To grasp a concept fully and thoroughly, especially  to be aware of the meaning of and  to be aware of the intent of.