Many words can make your speech sound simple and sometimes boring.
Here are a few more words to add to your repertoire.

to explain something difficult or mysterious- Elucidate
Kindly elucidate clause number four.

to banish or throw someone out of one’s country- Expatriate
The jury decided to expatriate the rowdy thief.

one who pretends to be what he is not- Hypocrite
He is such a hypocrite; never trust him.

not suitable for a place- Inapt
This table seems to be inapt for this corner.

something no longer in use- Obsolete
This gadget is obsolete; don’t invest in it.