amusing, boisterous, convivial, enjoyable, entertaining, lively
A group of seven things is a Septuple. Seven siblings born at the same time are Septuplets. A Heptagon has seven sides, but 'heptuple' is not correct. 'Septagon' can be used, but 'Heptagon' is much, much more common.
Acquire, gain, adopt, arise, arrive, attain, be able to/have the privilege of......, become, bring, buy, purchase, collect, discard, throw away, feel, find, locate, go, have, come down with, is, was, reach & receive
Some examples of unfamiliar words are frond, pax, specious, and obdurate. Sinecure and retinue are two other words that aren't used commonly.
According to wisegeek.com, the most used consonant in the English language is "t." Also, "t" is the most frequent letter that starts a word (in other words, there are more words that start with "t" than any other letter.) Heck--in this short answer alone, I've used 29 "t"s!
two
rather, preferably, alternately
since
Abscond.
Cooliousis
Special?
execute
uninteresting
Thou, ye, thee
Artillery,Armory
beneficial, handy
immediatelycurrentlyat this timepresentlypronto