tho

adverb1

1. •
   (dialect) Then; thereupon.

   • Tho went I near and found Master Reynard, that had left that he first read and sang, and began to play his old play. — 1481

article1

1. •
   (no longer used) The (plural form); those.

conjunction1

1. •
   (dialect) When.

pronoun1

1. •
   (no longer used) Those; they.

noun1

1. •
   Initialism of tritiated water (“³H-¹H-O, tritium-protium water”)