grou - high
- head-on collision
- head-on crash
- head-on protection
- head-on radiation
- head-penetration error
- head-space gas
- head-to-base fishing contour
- head-to-head addition
- head-to-head machines
- head-to-oxide [head-to-tape] contact
- head-to-tail addition
- head-to-tape spacing loss
- head-up (projection )display
- head-up (projection )display
- head-wheel
- head-wrap angle
- headability
- headache
- headache ball
- headache post