argillite
noun
ar·gil·lite ˈär-jə-ˌlīt 
: a compact argillaceous rock cemented by silica and having no slaty cleavage
Word History
First Known Use
1794, in the meaning defined above
- head mountains
- head of horns
- head of state
- head of steam
- head of the household
- head off
- head or tail
- head over ears
- head over heels
- head register
- head restraint
- head rhyme
- head rice
- head rod
- head rush
- head rushes
- head scab
- head schedule
- head sea
- head shop
- head shot
- head shots
- head smut
- head start
- head starts