Least is a superlative. I'm not sure if that answers what you were trying to ask or not, but if not, then what you were trying to ask doesn't make any sense.
'Least' is a comparison word. Compared to iron and lead yes cotton is least dense. Compares to oxygen gas and hydrogen gas, no it is not least dense.
The degrees of comparison for the word are: funnier and funniest.
The word "like" suggests a comparison in a sentence.
Comparison is a noun.
The word 'comparison' is a noun.
A comparison without using a connection word is called a metaphor. The connection word is like or as.
compare
It is the word "bad".
allegory
A syllable is only stressed in comparison to another syllable in the same word, therefore, only a word with at least two syllables would have either a stressed or an unstressed syllable, hence no, dry is not stressed.
epic simile
comparsion of huge