Yes! “Just a few words a day”…so I’ve been busy and will continue to be busy until (…?…) but, 出来るだけ! As much as possible!

ガリガリ, garigari

According to my ds, it is onomatopoeia for grinding or gnawing but, according to rikaichan it means selfish person or selfishness. Are they related? 心をガリガリかじる.

虫,むしば, mushiba

“cavity”, “decayed tooth”, the first kanji, 虫 (mushi), means “insect” and the second, 歯 (ha –> ba) means “tooth”. I wonder if the origin is from 虫 being used in compound words expressing things rotten or having gone bad or, was it once believed that a cavity or bad tooth was caused by a bug living inside?