I'm wondering if the sentence has a typo or it is really written as: The most amazing vacations are <u>to</u> places with...
Most sentences don't have that "to" in that part of the sentence or have it at all.
If that is the problem, then it looks like your question can be answered!
avail: use/take advantage of
discourse: <u>speak</u>/write/communicate or spoken/written communication
interjection: exclamation, addition of emotion in <u>speaker's</u> words
voluble: <u>speaking</u>/<u>spoken</u> fluently
