pro-drop 
(prōdrŏp′)
(prōdrŏp′)n.
The omission of a subject pronoun from a clause, occurring optionally in languages such as Spanish or Czech.
[PRO(NOUN) + DROP.]
- undercurrent
- undercut
- underdeveloped
- underdevelopment
- underdo
- underdog
- underdone
- underdrawers
- underdress
- underdrive
- undereducated
- underemphasis
- underemphasize
- underemployed
- underemployment
- underendowed
- underestimate
- underestimation
- underexpose
- underexposure
- underfeed
- under fire
- underflow
- underfoot
- underfund