Definition of thro' in US English:

thro'

(also thro)

adjective, preposition, & adverb

informal, literary
  • nonstandard spelling of through
    • ‘I have to worry thro' thick and thin to get all my clothes, crockery, chairs, clock, and so on.’
    • ‘Friendship, dearest creatures, will make at pleasure a safe bridge over the narrow seas; it will cut an easy passage thro' rocks and mountains, and make England and Italy one country.’

Pronunciation

thro'

/θru//THro͞o/