Words with 's' as the first letter that end with 'ax'

Is there a word from this page of word that starts with 's' and ends with 'ax' which might be deemed as unique?
'Surtax' is certainly the most peculiar word from our list of words that start with 's' and end with 'ax'. It means "An additional or extra tax. To impose an additional tax on.".

What's the total number of words one can create from this list?
From this page of words beginning with 's' and ending with 'ax', there are 18 combinations which are available.

What is the most common word for this page?
'Syntax' is the most well-known word from this that start with 's' and end with 'ax', ranked 39967^th most common word.

In Scrabble, what is the highest score you can get using this list of words with 's' as the 1st letter that end with 'ax'?
Our recommendation for a total of 25 points is to play the word 'saxifrax'.

How many characters does the largest word on this list consist of?
The largest word you can assemble from the combination specified is 'seropneumothorax', and it has 16 characters.