Far has got two comparative forms: farther or further. As you can see far is an irregular adjective.
far and far and far
Further and furthest.
The comparative of far may be further or farther.
"Litter" is a noun and a verb and, as such, does not have a comparative degree.
A comparative for the word ineffectual is more ineffectual.
smoother is comparative of word smooth.
afar, a good way, a long way, bit, deep, distant, end of rainbow, faraway, far-flung*, far-off, far piece, far-removed, good ways, long, middle of nowhere, miles, outlying, out-of-the-way*, piece, remote, removed, stone's throw, ways
farther
farther
farther
Dative ; hot Comparative ; hotter Superlative ; hottest
comparative