There are 20 words that start with 'testi'.
| testis | testier | testify |
| testily | testing | testicle |
| testiest | testicles | testified |
| testifier | testifies | testimony |
| testiness | testicular | testifiers |
| testifying | testimonial | testimonies |
| testinesses | testimonials | |
Note: These 20 words that start with 'testi' are found from the USA & Canada version of the tournament Scrabble word list.