Hexagon
through
azimuth
huckleberry
GURSHSAUGHSHRUGAGHASAARGHHUGSSURAHGASHHAGSAGHASUGHSHAGGUSHUGHSHAARSHAARAAHSUGHRUSHHAGRASHHUGRHUSGUARSAAHAGARSARGUSGAURSSUGARAHSHASSHARAGASASHRAHAHAAGARGAURGARSGUARAGASAURASRAGASHUHAHHARUGARAGSSAGARUGSRAGGASSAGRUGAGSAURAAGAGARSURAURSAAASAGARSRASSAUUSARASAA
You cannot make any seven letter words from these letters. The biggest words that can be made have four letters. They are:AgeeAghaGheeOgee
Seven letters - not eight letters listed in question Bushier
words with S H A P E: * pea * hash * ash * peas * he * she * sap * ape * has * phase
Death valley
Theorem uses the letters listed.
In English the largest word you can make is woaded, which uses six of the seven letters. There are no valid seven-letter combinations from the pattern a d d e h o w.
Hollow.
brushieBushierBushireHerbiusHuberisRubeishruibhseshirube