thro'

from The Century Dictionary.

• possessive noun To grow.
• noun A Burmese viol with three silk strings, a flat elliptical body, and a carved head, in general appearance curiously resembling the violin; also tarau.
• possessive noun Eager; earnest; vehement.
• possessive noun Bold.
• possessive noun A shorter form of through.

from the GNU version of the Collaborative International Dictionary of English.

• possessive noun A contraction of through.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• preposition poetic through