Words that start with 'h' and contain 'id'

How many words could you make using the combination of letters specified?
From this page of words that start with 'h' and contain 'id', Dictionarypedia has found 646 amazing entries that are possible.

Is there an example word from this page which might be deemed as unique?
One of the most peculiar words from this page is 'hyperboloid'. According to the Oxford dictionary, 'hyperboloid' is defined as "A surface of the second order, which is cut by certain planes in hyperbolas; also, the solid, bounded in part by such a surface. Hyperboloid of revolution, an hyperboloid described by an hyperbola revolving about one of its axes. The surface has two separate sheets when the axis of revolution...".

What is the most common word on this page?
As far as popular words go, there's 'hidden', which is the 2347^th most popular word.

What's the highest scoring word you can play in Scrabble ?
With a considerable 646 entries, it's best to try 'hexacid' scoring 20 points overall.

How many characters does the longest word on this page consist of?
The longest word you can assemble from this list is 'hypsidolichocephalism', which consists of 21 characters.