noun
ground beetle; carabid beetle
Refers to beetles of the family Carabidae, especially the subfamily Carabinae. In everyday contexts, often written in katakana.
庭で大きなオサムシを見つけた。
I found a large ground beetle in the garden.
オサムシは夜行性の昆虫です。
Ground beetles are nocturnal insects.
noun
millipede
Archaic use; in modern Japanese, millipede is normally ヤスデ.
古文書では「おさむし」がヤスデを指すことがある。
In old documents, おさむし can refer to a millipede.
The derivation is uncertain. The kanji 歩行虫 literally means 'walking insect', and 筬虫 refers to a reed or weaving tool, but these are likely ateji. The word is native Japanese.