One big word that uses most of the letters in comprehension is compression. These two words look similar, but have very different meanings. Another word that is similar to comprehension is comprehensive, which simply has a different suffix.
The letters do not spell any 6 letter word. However, the letters can be used to spell the words bid, big, dig and wig.
enormous
colossal
auditioning, dingdonging, indignation
A gust.
crate......
periwigs, speiring, spiering, swingier
counterfactual (14 letters) unsubstantial (13 letters) misconstrued (12 letters) My response to this question was counterfactually miscalculated, erroneous, fallaceous and unsubstantiated.
big
The timed word game "Big Boggle Game" can be purchased for around sixteen US$. One might be able to purchase the game used (and cheaper) at online auction houses. Big Boggle is a slightly changed version of the standard Boggle game (a 5x5 grid of letters instead of a 4x4 grid and a minimum word size of 4 letters instead of only 3).
Big
cause they can only choose one small letters or big letters so they choose big