i Register
In some senses, thru is marked as informal, US, UK, rare. Watch for register when choosing this word.
prep
Nonstandard spelling of through.
We wanted an overall treatment system that gave us optimum reliability and required a minimum of labor to operate - from primary clarifier thru sludge handling, …
… to respect human rights, then failing to explicitly define thru common understanding.
Abbreviation of through.
Eye dialect spelling of through.