Filthy, Used to Describe Collars or Kids' Knees
This page is the CodyCross answer for the clue below from Space Exploration, Group 915, Puzzle 1 (Keck Observatory).
Question is: Filthy, Used to Describe Collars or Kids' Knees
and the answer is: GRUBBY
Word Meaning:
GRUBBY — Dirty, unwashed, unclean.
Definitions from Wiktionary.